1
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Ren Y, Wang J, Zhang M, Wang Y, Cao Y, Kim DH, Lin Z. Locally Ordered Single-Atom Catalysts for Electrocatalysis. Angew Chem Int Ed Engl 2023:e202315003. [PMID: 37932862 DOI: 10.1002/anie.202315003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 11/04/2023] [Accepted: 11/06/2023] [Indexed: 11/08/2023]
Abstract
Single-atom catalysts manifest nearly 100 % atom utilization efficiency, well-defined active sites, and high selectivity. However, their practical applications are hindered by a low atom loading density, uncontrollable location, and ambiguous interaction with the support, thereby posing challenges to maximizing their electrocatalytic performance. To address these limitations, the ability to arrange randomly dispersed single atoms into locally ordered single-atom catalysts (LO-SACs) substantially influences the electronic effect between reactive sites and the support, the synergistic interaction among neighboring single atoms, the bonding energy of intermediates with reactive sites and the complexity of the mechanism. As such, it dramatically promotes reaction kinetics, reduces the energy barrier of the reaction, improves the performance of the catalyst and simplifies the reaction mechanism. In this review, firstly, we introduce a variety of compelling characteristics of LO-SACs as electrocatalysts. Subsequently, the synthetic strategies, characterization methods and applications of LO-SACs in electrocatalysis are discussed. Finally, the future opportunities and challenges are elaborated to encourage further exploration in this rapidly evolving field.
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Affiliation(s)
- Yujing Ren
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585, Singapore
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081 (P. R., China
| | - Jinyong Wang
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Mingyue Zhang
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585, Singapore
| | - Yuqing Wang
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585, Singapore
| | - Yuan Cao
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585, Singapore
| | - Dong Ha Kim
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul, 03760 (Republic of, Korea
| | - Zhiqun Lin
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585, Singapore
- Department of Chemistry and Nanoscience, Ewha Womans University, 52 Ewhayeodae-gil, Seodaemun-gu, Seoul, 03760 (Republic of, Korea
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2
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Abstract
Anisotropic heterostructures of colloidal nanocrystals embed size-, shape-, and composition-dependent electronic structure within variable three-dimensional morphology, enabling intricate design of solution-processable materials with high performance and programmable functionality. The key to designing and synthesizing such complex materials lies in understanding the fundamental thermodynamic and kinetic factors that govern nanocrystal growth. In this review, nanorod heterostructures, the simplest of anisotropic nanocrystal heterostructures, are discussed with respect to their growth mechanisms. The effects of crystal structure, surface faceting/energies, lattice strain, ligand sterics, precursor reactivity, and reaction temperature on the growth of nanorod heterostructures through heteroepitaxy and cation exchange reactions are explored with currently known examples. Understanding the role of various thermodynamic and kinetic parameters enables the controlled synthesis of complex nanorod heterostructures that can exhibit unique tailored properties. Selected application prospects arising from such capabilities are then discussed.
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Affiliation(s)
- Gryphon A Drake
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 United States
| | - Logan P Keating
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 United States
| | - Moonsub Shim
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 United States
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3
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Arora D, Tan HR, Wu WY, Chan Y. 2D-Oriented Attachment of 1D Colloidal Semiconductor Nanocrystals via an Etchant. NANO LETTERS 2022; 22:942-947. [PMID: 35089050 DOI: 10.1021/acs.nanolett.1c03680] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The oriented attachment (OA) of 0D semiconductor nanocrystals into 1D and 2D nanostructures with unique properties is useful for the fabrication of quantum confined nanomaterials that are otherwise difficult to produce by direct synthesis. Given that the OA of 1D nanocrystals such as nanorods generally produces linear chains, rod-couple structures, or clustered columns, linking them in a facet-specific manner to produce 2D structures is challenging. Here, we report that 1D Cu2-xS nanorods undergo etching on exposure to hexylphosphonic acid under mild heating, which results in an increased curvature and a reduction in surface ligands at those sites. This causes the nanorods to fuse via their basal tip facets into chains and then cojoin through diametrically opposed side facets, resulting in atomically coupled, 2D raftlike structures. The stepwise OA of 1D nanocrystals into 2D nanostructures illustrated here expands the range of nanoarchitectures that can be produced via solution-processed methods.
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Affiliation(s)
- Deepshikha Arora
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Hui Ru Tan
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Wen-Ya Wu
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Yinthai Chan
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
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4
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Wood JA, Liu Y, Widmer-Cooper A. Crystal nucleation in colloidal rod suspensions: The effect of depletant size. J Chem Phys 2021; 154:244505. [PMID: 34241344 DOI: 10.1063/5.0052623] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In order to better control the assembly of nanorods, knowledge of the pathways by which they form ordered structures is desirable. In this paper, we characterize crystal nucleation in suspensions of spherocylindrical rods with aspect ratio L/D = 2.3 in the presence of both small and large polymer depletants. Using a combination of Langevin dynamics and Monte Carlo simulations, together with biased sampling techniques, we show that the preferred pathway always involves the formation of monolayer assemblies irrespective of the volume fraction of the initial isotropic phase and the diameter of the depletants. This includes the previously neglected case of nucleation from the colloidal liquid phase and shows that the presence of depletion attraction can alter nucleation pathways even when the initial phase is dense.
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Affiliation(s)
- Jared A Wood
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Yawei Liu
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Asaph Widmer-Cooper
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
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5
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Qiang Y, Turner KT, Lee D. Polymer-infiltrated nanoplatelet films with nacre-like structure via flow coating and capillary rise infiltration (CaRI). NANOSCALE 2021; 13:5545-5556. [PMID: 33688884 DOI: 10.1039/d0nr08691f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Alignment of highly anisotropic nanomaterials in a polymer matrix can yield nanocomposites with unique mechanical and transport properties. Conventional methods of nanocomposite film fabrication are not well-suited for manufacturing composites with very high concentrations of anisotropic nanomaterials, potentially limiting the widespread implementation of these useful structures. In this work, we present a scalable approach to fabricate polymer-infiltrated nanoplatelet films (PINFs) based on flow coating and capillary rise infiltration (CaRI) and study the processing-structure-property relationship of these PINFs. We show that films with high aspect ratio (AR) gibbsite (Al (OH)3) nanoplatelets (NPTs) aligned parallel to the substrate can be prepared using a flow coating process. NPTs are highly aligned with a Herman's order parameter of 0.96 and a high packing fraction >80 vol%. Such packings show significantly higher fracture toughness compared to low AR nanoparticle (NP) packings. By depositing NPTs on a polymer film and subsequently annealing the bilayer above the glass transition temperature of the polymer, polymer infiltrates into the tortuous NPT packings though capillarity. We observe larger enhancement in the modulus, hardness and scratch resistance of NPT films upon polymer infiltration compared to NP packings. The excellent mechanical properties of such films benefit from both thermally promoted oxide bridge formation between NPTs as well as polymer infiltration increasing the strength of NPT contacts. Our approach is widely applicable to highly anisotropic nanomaterials and allows the generation of mechanically robust polymer nanocomposite films for a diverse set of applications.
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Affiliation(s)
- Yiwei Qiang
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
| | - Kevin T Turner
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. and Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Daeyeon Lee
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
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6
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Saruyama M, Sato R, Teranishi T. Transformations of Ionic Nanocrystals via Full and Partial Ion Exchange Reactions. Acc Chem Res 2021; 54:765-775. [PMID: 33533609 DOI: 10.1021/acs.accounts.0c00701] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
ConspectusElaborate chemical synthesis methods allow the production of various types of inorganic nanocrystals (NCs) with uniform shape and size distributions. Many single-step synthesis approaches, such as the reduction of metal ions, the decomposition of metal complexes, double replacement reactions, and hydrolysis, have been adapted to promote the generation of monodisperse metal and ionic NCs. However, the question has become, how can we synthesize NCs with thermodynamically metastable phases or very complex structures? The transformation of already-synthesized NCs via elemental substitutions, such as ion exchange reactions for ionic NCs and galvanic replacement reactions for metal NCs, can overcome the difficulties facing conventional one-step syntheses. In particular, NC ion exchange reactions have been studied with numerous combinations of foreign ions and ionic NCs with various shapes. They have been investigated extensively because the reactions proceed under relatively mild conditions thanks to the large surface-to-volume ratio of the NCs relative to their bulk form. The functionality of the resulting ionic NCs, including semiconducting and plasmonic properties, can be easily tuned in a wide range, from the visible to near-infrared. Because anions generally have much larger ionic radii than cations within the frameworks of NCs, the cation exchange reactions proceed much faster than the anion exchange reactions. For ionic NCs above a critical size, the anion framework remains intact, and the original shape of the parent NCs is retained throughout the cation exchange reaction. In contrast, the anion exchange reaction often provides the new NCs with unique structures, such as hollow or anisotropically phase-segregated assemblies.This Account focuses on the full and partial ion exchange reactions involving ionic NCs, which have been thoroughly investigated by our group and others while highlighting important aspects such as the preservation of appearance and dimensions. First, we discuss how each type of ion exchange reaction progresses to understand the morphologies and crystal structures of their final products. This discussion is supported by emphasizing important examples, which help to explore the formation of NCs with thermodynamically metastable phases and complex structures, and other significant features of the ion exchange reactions leading to structure-specific functions. As a special case, we examine how the shape-dependent anionic framework (surface anion sublattice and stacking pattern) of polyhedral Cu2O NCs determines the crystalline structure of the anion-exchanged products of hollow CuxS NCs. In addition, we review the characteristic anion exchange behavior of metal halide perovskite NCs observed in our laboratory and other laboratories. Finally, a general outline of the transformation of NCs via ion exchange reactions and future prospects in this field are provided.
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Affiliation(s)
- Masaki Saruyama
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Ryota Sato
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
| | - Toshiharu Teranishi
- Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan
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7
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Xia C, Pedrazo-Tardajos A, Wang D, Meeldijk JD, Gerritsen HC, Bals S, de Mello Donega C. Seeded Growth Combined with Cation Exchange for the Synthesis of Anisotropic Cu 2-x S/ZnS, Cu 2-x S, and CuInS 2 Nanorods. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2021; 33:102-116. [PMID: 33456135 PMCID: PMC7808334 DOI: 10.1021/acs.chemmater.0c02817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 11/03/2020] [Indexed: 06/12/2023]
Abstract
Colloidal copper(I) sulfide (Cu2-x S) nanocrystals (NCs) have attracted much attention for a wide range of applications because of their unique optoelectronic properties, driving scientists to explore the potential of using Cu2-x S NCs as seeds in the synthesis of heteronanocrystals to achieve new multifunctional materials. Herein, we developed a multistep synthesis strategy toward Cu2-x S/ZnS heteronanorods. The Janus-type Cu2-x S/ZnS heteronanorods are obtained by the injection of hexagonal high-chalcocite Cu2-x S seed NCs in a hot zinc oleate solution in the presence of suitable surfactants, 20 s after the injection of sulfur precursors. The Cu2-x S seed NCs undergo rapid aggregation and coalescence in the first few seconds after the injection, forming larger NCs that act as the effective seeds for heteronucleation and growth of ZnS. The ZnS heteronucleation occurs on a single (100) facet of the Cu2-x S seed NCs and is followed by fast anisotropic growth along a direction that is perpendicular to the c-axis, thus leading to Cu2-x S/ZnS Janus-type heteronanorods with a sharp heterointerface. Interestingly, the high-chalcocite crystal structure of the injected Cu2-x S seed NCs is preserved in the Cu2-x S segments of the heteronanorods because of the high-thermodynamic stability of this Cu2-x S phase. The Cu2-x S/ZnS heteronanorods are subsequently converted into single-component Cu2-x S and CuInS2 nanorods by postsynthetic topotactic cation exchange. This work expands the possibilities for the rational synthesis of colloidal multicomponent heteronanorods by allowing the design principles of postsynthetic heteroepitaxial seeded growth and nanoscale cation exchange to be combined, yielding access to a plethora of multicomponent heteronanorods with diameters in the quantum confinement regime.
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Affiliation(s)
- Chenghui Xia
- Debye
Institute for Nanomaterials Science, Utrecht
University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands
| | | | - Da Wang
- EMAT-University
of Antwerp, Groenenborgerlaan
171, B-2020 Antwerp, Belgium
| | - Johannes D. Meeldijk
- Debye
Institute for Nanomaterials Science, Utrecht
University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands
| | - Hans C. Gerritsen
- Debye
Institute for Nanomaterials Science, Utrecht
University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands
| | - Sara Bals
- EMAT-University
of Antwerp, Groenenborgerlaan
171, B-2020 Antwerp, Belgium
| | - Celso de Mello Donega
- Debye
Institute for Nanomaterials Science, Utrecht
University, P.O. Box 80000, 3508 TA Utrecht, The Netherlands
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8
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Gao Y, Wang L, Tian G, Zang S, Wang H, Niu J, Li LS. Morphology Controlled Synthesis of Composition Related Plasmonic CuCdS Alloy Nanocrystals. Front Chem 2021; 8:628536. [PMID: 33425861 PMCID: PMC7785700 DOI: 10.3389/fchem.2020.628536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 12/07/2020] [Indexed: 11/13/2022] Open
Abstract
Cu-based ternary alloy nanocrystals have emerged for extensive applications in solar cells, light-emitting devices (LEDs), and photoelectric detectors because of their low-toxicity, tunable band gaps, and large absorption coefficients. It is still an enormous challenge that regulating optical and electrical properties through changing their compositions and shapes in alloy nanocrystals. Herein, we present a facile method to synthesize CuCdS alloy nanocrystals (NCs) with tunable compositions and shapes at relatively low temperature. Different morphologies of monodisperse CuCdS nanocrystals are tailored successfully by simply adjusting the reaction temperature and Cu:Cd precursor molar ratio. The as-synthesized nanocrystals are of homogeneous alloy structures with uniform obvious lattice fringes throughout the whole particles rather than heterojunction structures. The localized surface plasmon resonance (LSPR) absorption peaks of CuCdS NCs are clearly observed and can be precisely tuned by varying the Cu:Cd molar ratio. Moreover, current-voltage (I-V) behaviors of different shaped CuCdS nanocrystals show certain rectification characteristics. The alloy CuCdS NCs with tunable shape, band gap, and compositionpossess a potential application in optoelectronic devices.
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Affiliation(s)
- Yan Gao
- Key Lab for Special Functional Materials, Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, School of Materials Science and Engineering, Henan University, Kaifeng, China
| | - Lei Wang
- Key Lab for Special Functional Materials, Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, School of Materials Science and Engineering, Henan University, Kaifeng, China
| | - Guimin Tian
- College of Materials Engineering, Henan University of Engineering, Zhengzhou, China
| | - Shuaipu Zang
- College of Materials Engineering, Henan University of Engineering, Zhengzhou, China
| | - Hongzhe Wang
- Key Lab for Special Functional Materials, Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, School of Materials Science and Engineering, Henan University, Kaifeng, China
| | - Jinzhong Niu
- College of Materials Engineering, Henan University of Engineering, Zhengzhou, China
| | - Lin Song Li
- Key Lab for Special Functional Materials, Ministry of Education, National and Local Joint Engineering Research Center for High-Efficiency Display and Lighting Technology, Collaborative Innovation Center of Nano Functional Materials and Applications, School of Materials Science and Engineering, Henan University, Kaifeng, China
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9
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Baiyasi R, Gallagher MJ, McCarthy LA, Searles EK, Zhang Q, Link S, Landes CF. Quantitative Analysis of Nanorod Aggregation and Morphology from Scanning Electron Micrographs Using SEMseg. J Phys Chem A 2020; 124:5262-5270. [DOI: 10.1021/acs.jpca.0c03190] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Rashad Baiyasi
- Department of Electrical and Computer Engineering, Rice University, MS 366, Houston, Texas 77005, United States
| | - Miranda J. Gallagher
- Department of Chemistry, Rice University, MS 60, Houston, Texas 77005, United States
| | - Lauren A. McCarthy
- Department of Chemistry, Rice University, MS 60, Houston, Texas 77005, United States
| | - Emily K. Searles
- Department of Chemistry, Rice University, MS 60, Houston, Texas 77005, United States
| | - Qingfeng Zhang
- Department of Chemistry, Rice University, MS 60, Houston, Texas 77005, United States
- Smalley-Curl Institute, Rice University, Houston, Texas 77005, United States
| | - Stephan Link
- Department of Electrical and Computer Engineering, Rice University, MS 366, Houston, Texas 77005, United States
- Department of Chemistry, Rice University, MS 60, Houston, Texas 77005, United States
- Smalley-Curl Institute, Rice University, Houston, Texas 77005, United States
| | - Christy F. Landes
- Department of Electrical and Computer Engineering, Rice University, MS 366, Houston, Texas 77005, United States
- Department of Chemistry, Rice University, MS 60, Houston, Texas 77005, United States
- Smalley-Curl Institute, Rice University, Houston, Texas 77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
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10
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Liu Y, Widmer-Cooper A. A versatile simulation method for studying phase behavior and dynamics in colloidal rod and rod-polymer suspensions. J Chem Phys 2019; 150:244508. [PMID: 31255071 DOI: 10.1063/1.5096193] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Here, we present an implicit-solvent model for dynamic simulations of hard-rod and rod-polymer suspensions. Individual rods are represented by a rigid linear chain consisting of overlapping spheres which interact through a pseudohard-core potential based on the cut-and-shifted Mie (generalized Lennard-Jones) potential with exponents (50, 49). In the rod-polymer suspensions, the polymers are modeled as freely interpenetrable spheres with respect to each other, while there is the pseudohard-core repulsion between the polymer and rod spheres. Dynamic simulations with this model are carried out with a dissipative particle dynamics (DPD) thermostat-each sphere is put in a larger DPD sphere and thus interacts with others via additional pairwise frictional and random forces-which captures the effects of Brownian forces due to the solvent while conserving local momentum. The phase behavior of these models, obtained from continuous compression and expansion simulations, reproduces previous predictions based on theoretical calculations and Monte Carlo simulations. Our method is suited to study dynamic processes in these suspensions, including nucleation and self-assembly, and can be readily extended to colloidal particles of different shapes and chemistry.
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Affiliation(s)
- Yawei Liu
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Asaph Widmer-Cooper
- ARC Centre of Excellence in Exciton Science, School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
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11
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Singraber A, Morawietz T, Behler J, Dellago C. Parallel Multistream Training of High-Dimensional Neural Network Potentials. J Chem Theory Comput 2019; 15:3075-3092. [PMID: 30995035 DOI: 10.1021/acs.jctc.8b01092] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Over the past years high-dimensional neural network potentials (HDNNPs), fitted to accurately reproduce ab initio potential energy surfaces, have become a powerful tool in chemistry, physics and materials science. Here, we focus on the training of the neural networks that lies at the heart of the HDNNP method. We present an efficient approach for optimizing the weight parameters of the neural network via multistream Kalman filtering, using potential energies and forces as reference data. In this procedure, the choice of the free parameters of the Kalman filter can have a significant impact on the fit quality. Carrying out a large parameter study, we determine optimal settings and demonstrate how to optimize training results of HDNNPs. Moreover, we illustrate our HDNNP training approach by revisiting previously presented fits for water and developing a new potential for copper sulfide. This material, accessible in computer simulations so far only via first-principles methods, forms a particularly complex solid structure at low temperatures and undergoes a phase transition to a superionic state upon heating. Analyzing MD simulations carried out with the Cu2S HDNNP, we confirm that the underlying ab initio reference method indeed reproduces this behavior.
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Affiliation(s)
- Andreas Singraber
- Faculty of Physics , University of Vienna , Boltzmanngasse 5 , Vienna , Austria
| | - Tobias Morawietz
- Department of Chemistry , Stanford University , Stanford , California 94305 , United States
| | - Jörg Behler
- Universität Göttingen , Institut für Physikalische Chemie, Theoretische Chemie , Tammannstraße 6 , 37077 Göttingen , Germany
| | - Christoph Dellago
- Faculty of Physics , University of Vienna , Boltzmanngasse 5 , Vienna , Austria
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12
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Lu MY, Hong MH, Ruan YM, Lu MP. Probing the photovoltaic properties of Ga-doped CdS–Cu2S core–shell heterostructured nanowire devices. Chem Commun (Camb) 2019; 55:5351-5354. [DOI: 10.1039/c8cc10316j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study Ga-doped cadmium sulfide (CdS) nanowires (NWs) were grown through chemical vapor deposition.
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Affiliation(s)
- Ming-Yen Lu
- Department of Materials Science and Engineering
- National Tsing Hua University
- Hsinchu 300
- Taiwan
- High Entropy Materials Center
| | - Meng-Hsiang Hong
- Graduate Institute of Opto-Mechatronics
- National Chung Cheng University
- Chia-Yi 62102
- Taiwan
| | - Yen-Min Ruan
- Graduate Institute of Opto-Mechatronics
- National Chung Cheng University
- Chia-Yi 62102
- Taiwan
| | - Ming-Pei Lu
- National Nano Device Laboratories
- Hsinchu 300
- Taiwan
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13
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Lateral epitaxial heterojunctions in single nanowires fabricated by masked cation exchange. Nat Commun 2018; 9:505. [PMID: 29410426 PMCID: PMC5802801 DOI: 10.1038/s41467-018-02878-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 01/05/2018] [Indexed: 11/12/2022] Open
Abstract
Cation exchange is a versatile tool to control the composition of nanocrystals, and recently deterministic patterning could be achieved by combining it with lithography techniques. Regarding single nanocrystal structures, such spatial control of cation exchange enables the design of heterostructures, which can be integrated in functional optoelectronic elements. In this work, we fabricate nanowire CdSe/Cu2Se heterojunctions by masking cation exchange via electron-beam irradiation, such that cation exchange proceeds only in the non-irradiated sections. Interestingly, the heterojunction interfaces are almost atomically sharp, and the adjacent CdSe and Cu2Se domains exhibit epitaxial relationships. We show that the cation exchange at the CdSe/Cu2Se interface is only possible if the displaced Cd2+ ions can radially out-diffuse to the solution phase. If this exit pathway is blocked, the cation exchange cannot occur. Our technique allows one to transform already contacted single nanowires, and the obtained heterojunction nanowires manifest a noticeable gain in conductance. Lateral structuring of the chemical composition of nanowires can enhance their functionality for photoconductive devices. Here, the authors fabricate CdSe/Cu2Se nanowire heterojunctions with atomically sharp interfaces and epitaxial relationships by a masked cation exchange approach.
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14
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Singh A, Singh A, Ong GK, Jones MR, Nordlund D, Bustillo K, Ciston J, Alivisatos AP, Milliron DJ. Dopant Mediated Assembly of Cu 2ZnSnS 4 Nanorods into Atomically Coupled 2D Sheets in Solution. NANO LETTERS 2017; 17:3421-3428. [PMID: 28485598 DOI: 10.1021/acs.nanolett.7b00232] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Assembly of anisotropic nanocrystals into ordered superstructures is an area of intense research interest due to its relevance to bring nanocrystal properties to macroscopic length scales and to impart additional collective properties owing to the superstructure. Numerous routes have been explored to assemble such nanocrystal superstructures ranging from self-directed to external field-directed methods. Most of the approaches require sensitive control of experimental parameters that are largely environmental and require extra processing steps, increasing complexity and limiting reproducibility. Here, we demonstrate a simple approach to assemble colloidal nanorods in situ, wherein dopant incorporation during the particle synthesis results in the formation of preassembled 2D sheets of close-packed ordered arrays of vertically oriented nanorods in solution.
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Affiliation(s)
- Ajay Singh
- McKetta Department of Chemical Engineering, The University of Texas at Austin , 200 East Dean Keeton Street, Austin, Texas 78712, United States
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Amita Singh
- McKetta Department of Chemical Engineering, The University of Texas at Austin , 200 East Dean Keeton Street, Austin, Texas 78712, United States
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Gary K Ong
- McKetta Department of Chemical Engineering, The University of Texas at Austin , 200 East Dean Keeton Street, Austin, Texas 78712, United States
- Department of Materials Science and Engineering, University of California-Berkeley , Berkeley, California 94720, United States
| | - Matthew R Jones
- Department of Chemistry, University of California-Berkeley , Berkeley, California 94720, United States
| | - Dennis Nordlund
- Stanford Synchrotron Radiation Lightsource , P.O. Box 20450, Stanford, California 94309, United States
| | - Karen Bustillo
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Jim Ciston
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory , 1 Cyclotron Road, Berkeley, California 94720, United States
| | - A Paul Alivisatos
- Department of Materials Science and Engineering, University of California-Berkeley , Berkeley, California 94720, United States
- Department of Chemistry, University of California-Berkeley , Berkeley, California 94720, United States
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
- Kavli Energy NanoScience Institute , Berkeley, California 94720, United States
| | - Delia J Milliron
- McKetta Department of Chemical Engineering, The University of Texas at Austin , 200 East Dean Keeton Street, Austin, Texas 78712, United States
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15
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Coughlan C, Ibáñez M, Dobrozhan O, Singh A, Cabot A, Ryan KM. Compound Copper Chalcogenide Nanocrystals. Chem Rev 2017; 117:5865-6109. [PMID: 28394585 DOI: 10.1021/acs.chemrev.6b00376] [Citation(s) in RCA: 331] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review captures the synthesis, assembly, properties, and applications of copper chalcogenide NCs, which have achieved significant research interest in the last decade due to their compositional and structural versatility. The outstanding functional properties of these materials stems from the relationship between their band structure and defect concentration, including charge carrier concentration and electronic conductivity character, which consequently affects their optoelectronic, optical, and plasmonic properties. This, combined with several metastable crystal phases and stoichiometries and the low energy of formation of defects, makes the reproducible synthesis of these materials, with tunable parameters, remarkable. Further to this, the review captures the progress of the hierarchical assembly of these NCs, which bridges the link between their discrete and collective properties. Their ubiquitous application set has cross-cut energy conversion (photovoltaics, photocatalysis, thermoelectrics), energy storage (lithium-ion batteries, hydrogen generation), emissive materials (plasmonics, LEDs, biolabelling), sensors (electrochemical, biochemical), biomedical devices (magnetic resonance imaging, X-ray computer tomography), and medical therapies (photochemothermal therapies, immunotherapy, radiotherapy, and drug delivery). The confluence of advances in the synthesis, assembly, and application of these NCs in the past decade has the potential to significantly impact society, both economically and environmentally.
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Affiliation(s)
- Claudia Coughlan
- Department of Chemical Sciences and Bernal Institute, University of Limerick , Limerick, Ireland
| | - Maria Ibáñez
- Catalonia Energy Research Institute - IREC, Sant Adria de Besos , Jardins de les Dones de Negre n.1, Pl. 2, 08930 Barcelona, Spain
| | - Oleksandr Dobrozhan
- Catalonia Energy Research Institute - IREC, Sant Adria de Besos , Jardins de les Dones de Negre n.1, Pl. 2, 08930 Barcelona, Spain.,Department of Electronics and Computing, Sumy State University , 2 Rymskogo-Korsakova st., 40007 Sumy, Ukraine
| | - Ajay Singh
- Materials Physics & Applications Division: Center for Integrated Nanotechnologies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Andreu Cabot
- Catalonia Energy Research Institute - IREC, Sant Adria de Besos , Jardins de les Dones de Negre n.1, Pl. 2, 08930 Barcelona, Spain.,ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Kevin M Ryan
- Department of Chemical Sciences and Bernal Institute, University of Limerick , Limerick, Ireland
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16
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Albrecht W, Goris B, Bals S, Hutter EM, Vanmaekelbergh D, van Huis MA, van Blaaderen A. Morphological and chemical transformations of single silica-coated CdSe/CdS nanorods upon fs-laser excitation. NANOSCALE 2017; 9:4810-4818. [PMID: 28352861 DOI: 10.1039/c6nr09879g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Radiation-induced modifications of nanostructures are of fundamental interest and constitute a viable out-of-equilibrium approach to the development of novel nanomaterials. Herein, we investigated the structural transformation of silica-coated CdSe/CdS nanorods (NRs) under femtosecond (fs) illumination. By comparing the same nanorods before and after illumination with different fluences we found that the silica-shell did not only enhance the stability of the NRs but that the confinement of the NRs also led to novel morphological and chemical transformations. Whereas uncoated CdSe/CdS nanorods were found to sublimate under such excitations the silica-coated nanorods broke into fragments which deformed towards a more spherical shape. Furthermore, CdS decomposed which led to the formation of metallic Cd, confirmed by high-resolution electron microscopy and energy dispersive X-ray spectrometry (EDX), whereby an epitaxial interface with the remaining CdS lattice was formed. Under electron beam exposure similar transformations were found to take place which we followed in situ.
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Affiliation(s)
- Wiebke Albrecht
- Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
| | - Bart Goris
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Sara Bals
- Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Eline M Hutter
- Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
| | - Daniel Vanmaekelbergh
- Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
| | - Marijn A van Huis
- Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
| | - Alfons van Blaaderen
- Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
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17
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Veldhuis SA, Boix PP, Yantara N, Li M, Sum TC, Mathews N, Mhaisalkar SG. Perovskite Materials for Light-Emitting Diodes and Lasers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:6804-34. [PMID: 27214091 DOI: 10.1002/adma.201600669] [Citation(s) in RCA: 502] [Impact Index Per Article: 62.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/10/2016] [Indexed: 05/22/2023]
Abstract
Organic-inorganic hybrid perovskites have cemented their position as an exceptional class of optoelectronic materials thanks to record photovoltaic efficiencies of 22.1%, as well as promising demonstrations of light-emitting diodes, lasers, and light-emitting transistors. Perovskite materials with photoluminescence quantum yields close to 100% and perovskite light-emitting diodes with external quantum efficiencies of 8% and current efficiencies of 43 cd A(-1) have been achieved. Although perovskite light-emitting devices are yet to become industrially relevant, in merely two years these devices have achieved the brightness and efficiencies that organic light-emitting diodes accomplished in two decades. Further advances will rely decisively on the multitude of compositional, structural variants that enable the formation of lower-dimensionality layered and three-dimensional perovskites, nanostructures, charge-transport materials, and device processing with architectural innovations. Here, the rapid advancements in perovskite light-emitting devices and lasers are reviewed. The key challenges in materials development, device fabrication, operational stability are addressed, and an outlook is presented that will address market viability of perovskite light-emitting devices.
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Affiliation(s)
- Sjoerd A Veldhuis
- Energy Research Institute at Nanyang Technological University (ERI@N), Research Techno Plaza, X-Frontier Block Level 5, 50 Nanyang Drive, Singapore, 637553, Singapore
| | - Pablo P Boix
- Energy Research Institute at Nanyang Technological University (ERI@N), Research Techno Plaza, X-Frontier Block Level 5, 50 Nanyang Drive, Singapore, 637553, Singapore
| | - Natalia Yantara
- Energy Research Institute at Nanyang Technological University (ERI@N), Research Techno Plaza, X-Frontier Block Level 5, 50 Nanyang Drive, Singapore, 637553, Singapore
| | - Mingjie Li
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Tze Chien Sum
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore
| | - Nripan Mathews
- Energy Research Institute at Nanyang Technological University (ERI@N), Research Techno Plaza, X-Frontier Block Level 5, 50 Nanyang Drive, Singapore, 637553, Singapore
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Subodh G Mhaisalkar
- Energy Research Institute at Nanyang Technological University (ERI@N), Research Techno Plaza, X-Frontier Block Level 5, 50 Nanyang Drive, Singapore, 637553, Singapore
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore
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18
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Kriegel I, Scotognella F, Soavi G, Brescia R, Rodríguez-Fernández J, Feldmann J, Lanzani G, Tassone F. Delayed electron relaxation in CdTe nanorods studied by spectral analysis of the ultrafast transient absorption. Chem Phys 2016. [DOI: 10.1016/j.chemphys.2015.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Amit Y, Li Y, Frenkel AI, Banin U. From Impurity Doping to Metallic Growth in Diffusion Doping: Properties and Structure of Silver-Doped InAs Nanocrystals. ACS NANO 2015; 9:10790-10800. [PMID: 26390173 DOI: 10.1021/acsnano.5b03044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Tuning of the electronic properties of presynthesized colloidal semiconductor nanocrystals (NCs) by doping plays a key role in the prospect of implementing them in printed electronics devices such as transistors and photodetectors. While such impurity doping reactions have already been introduced, the understanding of the doping process, the nature of interaction between the impurity and host atoms, and the conditions affecting the solubility limit of impurities in nanocrystals are still unclear. Here, we used a postsynthesis diffusion-based doping reaction to introduce Ag impurities into InAs NCs. Optical absorption spectroscopy and analytical inductively coupled plasma mass spectroscopy (ICP-MS) were used to present a two-stage doping model consisting of a "doping region" and a "growth region", depending on the impurity to NC ratio in the reaction vessel. X-ray absorption fine-structure (XAFS) spectroscopy was employed to determine the impurity location and correlate between the structural and electronic properties for different sizes of InAs NCs and dopant concentrations. The resulting structural model describes a heterogeneous system where the impurities initially dope the NC, by substituting for In atoms near the surface of the NC, until the "solubility limit" is reached, after which the rapid growth and formation of metallic structures are identified.
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Affiliation(s)
| | - Yuanyuan Li
- Department of Physics, Yeshiva University , New York, New York 10016, United States
| | - Anatoly I Frenkel
- Department of Physics, Yeshiva University , New York, New York 10016, United States
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20
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Yu X, Liu J, Genç A, Ibáñez M, Luo Z, Shavel A, Arbiol J, Zhang G, Zhang Y, Cabot A. Cu₂ZnSnS₄-Ag₂S Nanoscale p-n Heterostructures as Sensitizers for Photoelectrochemical Water Splitting. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:10555-10561. [PMID: 26343896 DOI: 10.1021/acs.langmuir.5b02490] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
A cation exchange-based route was used to produce Cu2ZnSnS4 (CZTS)-Ag2S nanoparticles with controlled composition. We report a detailed study of the formation of such CZTS-Ag2S nanoheterostructures and of their photocatalytic properties. When compared to pure CZTS, the use of nanoscale p-n heterostructures as light absorbers for photocatalytic water splitting provides superior photocurrents. We associate this experimental fact to a higher separation efficiency of the photogenerated electron-hole pairs. We believe this and other type-II nanoheterostructures will open the door to the use of CZTS, with excellent light absorption properties and made of abundant and environmental friendly elements, to the field of photocatalysis.
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Affiliation(s)
- Xuelian Yu
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences , 100083 Beijing, P. R. China
- Catalonia Energy Research Institute - IREC , 08930 Sant Adria del Besos, Barcelona, Spain
| | - Jingjing Liu
- Key Laboratory of Green Process and Engineering, Chinese Academy of Sciences , 100190 Beijing, P. R. China
| | - Aziz Genç
- Institut Català de Nanociència i Nanotecnologia, ICN2 , Campus de la UAB, 08193 Bellaterra, Spain
| | - Maria Ibáñez
- Catalonia Energy Research Institute - IREC , 08930 Sant Adria del Besos, Barcelona, Spain
| | - Zhishan Luo
- Catalonia Energy Research Institute - IREC , 08930 Sant Adria del Besos, Barcelona, Spain
| | - Alexey Shavel
- Catalonia Energy Research Institute - IREC , 08930 Sant Adria del Besos, Barcelona, Spain
| | - Jordi Arbiol
- Institut Català de Nanociència i Nanotecnologia, ICN2 , Campus de la UAB, 08193 Bellaterra, Spain
- Institució Catalana de Recerca i Estudis Avançats - ICREA, 08010 Barcelona, Spain
| | - Guangjin Zhang
- Key Laboratory of Green Process and Engineering, Chinese Academy of Sciences , 100190 Beijing, P. R. China
| | - Yihe Zhang
- Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences , 100083 Beijing, P. R. China
| | - Andreu Cabot
- Catalonia Energy Research Institute - IREC , 08930 Sant Adria del Besos, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats - ICREA, 08010 Barcelona, Spain
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21
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Nedelcu G, Protesescu L, Yakunin S, Bodnarchuk MI, Grotevent MJ, Kovalenko MV. Fast Anion-Exchange in Highly Luminescent Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, I). NANO LETTERS 2015; 15:5635-5640. [PMID: 26207728 PMCID: PMC4538456 DOI: 10.1021/acs.nanolett.5b02404] [Citation(s) in RCA: 937] [Impact Index Per Article: 104.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 07/23/2015] [Indexed: 05/18/2023]
Abstract
Postsynthetic chemical transformations of colloidal nanocrystals, such as ion-exchange reactions, provide an avenue to compositional fine-tuning or to otherwise inaccessible materials and morphologies. While cation-exchange is facile and commonplace, anion-exchange reactions have not received substantial deployment. Here we report fast, low-temperature, deliberately partial, or complete anion-exchange in highly luminescent semiconductor nanocrystals of cesium lead halide perovskites (CsPbX3, X = Cl, Br, I). By adjusting the halide ratios in the colloidal nanocrystal solution, the bright photoluminescence can be tuned over the entire visible spectral region (410-700 nm) while maintaining high quantum yields of 20-80% and narrow emission line widths of 10-40 nm (from blue to red). Furthermore, fast internanocrystal anion-exchange is demonstrated, leading to uniform CsPb(Cl/Br)3 or CsPb(Br/I)3 compositions simply by mixing CsPbCl3, CsPbBr3, and CsPbI3 nanocrystals in appropriate ratios.
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Affiliation(s)
- Georgian Nedelcu
- Institute of Inorganic
Chemistry, Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa − Swiss Federal Laboratories for Materials Science and
Technology, CH-8600 Dübendorf, Switzerland
| | - Loredana Protesescu
- Institute of Inorganic
Chemistry, Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa − Swiss Federal Laboratories for Materials Science and
Technology, CH-8600 Dübendorf, Switzerland
| | - Sergii Yakunin
- Institute of Inorganic
Chemistry, Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa − Swiss Federal Laboratories for Materials Science and
Technology, CH-8600 Dübendorf, Switzerland
| | - Maryna I. Bodnarchuk
- Institute of Inorganic
Chemistry, Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa − Swiss Federal Laboratories for Materials Science and
Technology, CH-8600 Dübendorf, Switzerland
| | - Matthias J. Grotevent
- Institute of Inorganic
Chemistry, Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Maksym V. Kovalenko
- Institute of Inorganic
Chemistry, Department of Chemistry and Applied Bioscience, ETH Zürich, CH-8093 Zürich, Switzerland
- Laboratory for Thin Films and Photovoltaics, Empa − Swiss Federal Laboratories for Materials Science and
Technology, CH-8600 Dübendorf, Switzerland
- E-mail:
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22
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Nanayakkara SU, van de Lagemaat J, Luther JM. Scanning Probe Characterization of Heterostructured Colloidal Nanomaterials. Chem Rev 2015. [PMID: 26196958 DOI: 10.1021/cr500280t] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Sanjini U. Nanayakkara
- National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
| | - Jao van de Lagemaat
- National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
| | - Joseph M. Luther
- National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
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23
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Wong AB, Brittman S, Yu Y, Dasgupta NP, Yang P. Core-Shell CdS-Cu₂S Nanorod Array Solar Cells. NANO LETTERS 2015; 15:4096-4101. [PMID: 25993088 DOI: 10.1021/acs.nanolett.5b01203] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
As an earth-abundant p-type semiconductor, copper sulfide (Cu2S) is an attractive material for application in photovoltaic devices. However, it suffers from a minority carrier diffusion length that is less than the length required for complete light absorption. Core-shell nanowires and nanorods have the potential to alleviate this difficulty because they decouple the length scales of light absorption and charge collection. To achieve this geometry using Cu2S, cation exchange was applied to an array of CdS nanorods to produce well-defined CdS-Cu2S core-shell nanorods. Previous work has demonstrated single-nanowire photovoltaic devices from this material system, but in this work, the cation exchange chemistry has been applied to nanorod arrays to produce ensemble-level devices with microscale sizes. The core-shell nanorod array devices show power conversion efficiencies of up to 3.8%. In addition, these devices are stable when measured in air after nearly one month of storage in a desiccator. These results are a first step in the development of large-area nanostructured Cu2S-based photovoltaics that can be processed from solution.
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Affiliation(s)
- Andrew Barnabas Wong
- †Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- ‡Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Sarah Brittman
- †Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- ‡Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Yi Yu
- †Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- ‡Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Neil P Dasgupta
- †Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - Peidong Yang
- †Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
- ‡Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- §Kavli Energy Nanosciences Institute, Berkeley, California 94720, United States
- ∥Department of Materials Science and Engineering, University of California, Berkeley, California 94720, United States
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24
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Paik T, Diroll BT, Kagan CR, Murray CB. Binary and Ternary Superlattices Self-Assembled from Colloidal Nanodisks and Nanorods. J Am Chem Soc 2015; 137:6662-9. [DOI: 10.1021/jacs.5b03234] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Taejong Paik
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Benjamin T. Diroll
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Cherie R. Kagan
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department
of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department
of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Christopher B. Murray
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department
of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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25
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Singh A, Singh A, Ciston J, Bustillo K, Nordlund D, Milliron DJ. Synergistic Role of Dopants on the Morphology of Alloyed Copper Chalcogenide Nanocrystals. J Am Chem Soc 2015; 137:6464-7. [DOI: 10.1021/jacs.5b02880] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Ajay Singh
- McKetta
Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- The
Molecular Foundry and §National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Amita Singh
- McKetta
Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- The
Molecular Foundry and §National Center for Electron Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | | | | | - Dennis Nordlund
- Stanford Synchrotron Radiation Lightsource, Stanford, California 94309, United States
| | - Delia J. Milliron
- McKetta
Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
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26
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Diroll BT, Doan-Nguyen VVT, Cargnello M, Gaulding EA, Kagan CR, Murray CB. X-ray mapping of nanoparticle superlattice thin films. ACS NANO 2014; 8:12843-12850. [PMID: 25478642 DOI: 10.1021/nn5062832] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We combine grazing-incidence and transmission small-angle X-ray diffraction with electron microscopy studies to characterize the structure of nanoparticle films with long-range order. Transmission diffraction is used to collect in-plane diffraction data from single grains and locally aligned nanoparticle superlattice films. Systematic mapping of samples can be achieved by translating the sample in front of the X-ray beam with a spot size selected to be on the order of superlattice grain features. This allows a statistical determination of superlattice grain size and size distribution over much larger areas than typically accessible with electron microscopy. Transmission X-ray measurements enables spatial mapping of the grain size, orientation, uniformity, strain, or crystal projections and polymorphs. We expand this methodology to binary nanoparticle superlattice and nanorod superlattice films. This study provides a framework for characterization of nanoparticle superlattices over large areas which complements or expands microstructure information from real-space imaging.
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Affiliation(s)
- Benjamin T Diroll
- Department of Chemistry, ‡Department of Materials Science and Engineering, and §Department of Electrical and Systems Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
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27
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Kundu S, Kundu P, Van Tendeloo G, Ravishankar N. Au2S(x)/CdS nanorods by cation exchange: mechanistic insights into the competition between cation-exchange and metal ion reduction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:3895-3900. [PMID: 24889074 DOI: 10.1002/smll.201400524] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/08/2014] [Indexed: 06/03/2023]
Abstract
It is well known that metals with higher electron affinity like Au tend to undergo reduction rather than cation-exchange. It is experimentally shown that under certain conditions cation-exchange is dominant over reduction. Thermodynamic calculation further consolidates the understanding and paves the way for better predictability of cation-exchange/reduction reactions for other systems.
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Affiliation(s)
- Subhajit Kundu
- Materials Research Centre, Indian Institute of Science, C.V. Raman Avenue, Bangalore, 560012, India
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28
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Yao L, Lu X, Chen S, Watkins JJ. Formation of Helical Phases in Achiral Block Copolymers by Simple Addition of Small Chiral Additives. Macromolecules 2014. [DOI: 10.1021/ma501714g] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Li Yao
- Department
of Polymer Science and Engineering, University of Massachusetts Amherst, 120 Governors Drive, Amherst, Massachusetts 01003, United States
| | - Xuemin Lu
- Department
of Polymer Science and Engineering, University of Massachusetts Amherst, 120 Governors Drive, Amherst, Massachusetts 01003, United States
- School
of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai 200240, P. R. China
| | - Shuangshuang Chen
- School
of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai 200240, P. R. China
| | - James J. Watkins
- Department
of Polymer Science and Engineering, University of Massachusetts Amherst, 120 Governors Drive, Amherst, Massachusetts 01003, United States
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29
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Majeski MW, Bolotin IL, Hanley L. Cluster beam deposition of Cu(2-X)S nanoparticles into organic thin films. ACS APPLIED MATERIALS & INTERFACES 2014; 6:12901-12908. [PMID: 24977326 DOI: 10.1021/am5028428] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Bulk-heterojunction films composed of semiconductor nanoparticles blended with organic oligomers are of interest for photovoltaic and other applications. Cu2-XS nanoparticles were cluster beam deposited into thermally evaporated pentacene or quaterthiophene to create bulk-heterojunction thin films. The nanoparticle stoichiometry, morphology, and chemistry within these all-gas phase deposited films were characterized by X-ray photoelectron spectroscopy (XPS) and electron microscopy. Cu2-XS nanoparticles were (at most) only slightly copper-deficient with respect to Cu2S; ∼2.5 nm diameter, unoxidized Cu2-XS nanoparticles formed in both pentacene and quaterthiophene, as the matrix was not observed to impact the nanoparticle morphology or chemical structure. Cluster beam deposition allowed direct control of the nanoparticle stoichiometry and nanoparticle:organic ratio. Chemical states or Wagner plots were combined with other XPS data analysis strategies to determine the metal oxidation state, indicating that Cu(I) was predominant over Cu(II) in the Cu2-XS nanoparticles.
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Affiliation(s)
- Michael W Majeski
- Department of Chemistry (MC 111), University of Illinois at Chicago , Chicago, Illinois 60607, United States
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30
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Liakakos N, Gatel C, Blon T, Altantzis T, Lentijo-Mozo S, Garcia-Marcelot C, Lacroix LM, Respaud M, Bals S, Van Tendeloo G, Soulantica K. Co-Fe nanodumbbells: synthesis, structure, and magnetic properties. NANO LETTERS 2014; 14:2747-2754. [PMID: 24742331 DOI: 10.1021/nl500734k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report the solution phase synthesis, the structural analysis, and the magnetic properties of hybrid nanostructures combining two magnetic metals. These nano-objects are characterized by a remarkable shape, combining Fe nanocubes on Co nanorods. The topological composition, the orientation relationship, and the growth steps have been studied by advanced electron microscopy techniques, such as HRTEM, electron tomography, and state-of-the-art 3-dimensional elemental mapping by EDX tomography. The soft iron nanocubes behave as easy nucleation centers that induce the magnetization reversal of the entire nanohybrid, leading to a drastic modification of the overall effective magnetic anisotropy.
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Affiliation(s)
- Nikos Liakakos
- Université de Toulouse ; INSA, UPS, LPCNO, CNRS-UMR5215, 135 avenue de Rangueil, 31077 Toulouse, France
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31
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Miszta K, Greullet F, Marras S, Prato M, Toma A, Arciniegas M, Manna L, Krahne R. Nanocrystal film patterning by inhibiting cation exchange via electron-beam or X-ray lithography. NANO LETTERS 2014; 14:2116-2122. [PMID: 24593136 DOI: 10.1021/nl500349j] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this Letter we report patterning of colloidal nanocrystal films that combines direct e-beam (electron beam) writing with cation exchange. The e-beam irradiation causes cross-linking of the ligand molecules present at the nanocrystal surface, and the cross-linked molecules act as a mask for further processing. Consequently, in the following step of cation exchange, which is performed by directly dipping the substrate in a solution containing the new cations, the regions that have not been exposed to the electron beam are chemically transformed, while the exposed ones remain unchanged. This selective protection allows the design of patterns that are formed by chemically different nanocrystals, yet in a homogeneous nanocrystal film. Spatially resolved compositional analysis by energy-dispersive X-ray spectroscopy (EDS) corroborates that the selective exchange occurs only in the nonirradiated regions. We demonstrate the utility of this lithography approach by fabricating conductive wires and luminescent patterns in CdSe/CdS nanocrystal films by converting nonirradiated regions to Cu2-xSe/Cu2-xS. Furthermore, we show that X-ray irradiation too can lead to protection from cation exchange.
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Affiliation(s)
- Karol Miszta
- Istituto Italiano di Tecnologia , Via Morego 30, 16163 Genova, Italy
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32
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Bera A, Dey S, Pal AJ. Band mapping across a pn-junction in a nanorod by scanning tunneling microscopy. NANO LETTERS 2014; 14:2000-2005. [PMID: 24588335 DOI: 10.1021/nl500081m] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We map band-edges across a pn-junction that was formed in a nanorod. We form a single junction between p-type Cu2S and n-type CdS through a controlled cationic exchange process of CdS nanorods. We characterize nanorods of the individual materials and the single junction in a nanorod with an ultrahigh vacuum scanning tunneling microscope (UHV-STM) at 77 K. From scanning tunneling spectroscopy and correspondingly the density of states (DOS) spectra, we determine the conduction and valence band-edges at different points across the junction and the individual nanorods. We could map the band-diagram of nanorod-junctions to bring out the salient features of a diode, such as p- and n-sections, band-bending, depletion region, albeit interestingly in the nanoscale.
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Affiliation(s)
- Abhijit Bera
- Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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33
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van der Stam W, Gantapara AP, Akkerman QA, Soligno G, Meeldijk JD, van Roij R, Dijkstra M, de Mello Donega C. Self-assembly of colloidal hexagonal bipyramid- and bifrustum-shaped ZnS nanocrystals into two-dimensional superstructures. NANO LETTERS 2014; 14:1032-7. [PMID: 24433112 DOI: 10.1021/nl4046069] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We present a combined experimental, theoretical, and simulation study on the self-assembly of colloidal hexagonal bipyramid- and hexagonal bifrustum-shaped ZnS nanocrystals (NCs) into two-dimensional superlattices. The simulated NC superstructures are in good agreement with the experimental ones. This shows that the self-assembly process is primarily driven by minimization of the interfacial free-energies and maximization of the packing density. Our study shows that a small truncation of the hexagonal bipyramids is sufficient to change the symmetry of the resulting superlattice from hexagonal to tetragonal, highlighting the crucial importance of precise shape control in the fabrication of functional metamaterials by self-assembly of colloidal NCs.
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Affiliation(s)
- Ward van der Stam
- Condensed Matter and Interfaces and §Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University , 3508 TA Utrecht, The Netherlands
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34
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Jen-La Plante I, Teitelboim A, Pinkas I, Oron D, Mokari T. Exciton Quenching Due to Copper Diffusion Limits the Photocatalytic Activity of CdS/Cu2S Nanorod Heterostructures. J Phys Chem Lett 2014; 5:590-6. [PMID: 26276614 DOI: 10.1021/jz500041g] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The formation of donor/acceptor junctions in hybrid nanomaterials is predicted to enhance photocatalytic activity as compared to single-component semiconductor systems. Specifically, nanomaterials containing a junction of n-type cadmium sulfide (CdS) and p-type copper sulfide (Cu2S) formed via cation exchange have been proposed as potential photocatalysts for reactions such as water splitting. Herein, we study the elemental distribution of Cu within these nanostructures using analytical transmission electron microscopy techniques. The resulting effects of this elemental distribution on photocatalytic activity and charge dynamics were further studied using a model photoreduction reaction and transient absorption spectroscopy. We find that copper diffusion in the hybrid nanostructure quenches the exciton lifetime and results in low photocatalytic activity; however, this effect can be partially mitigated via selective extraction. These results provide a deeper understanding of the physical processes within these hybrid nanostructures and will lead to more rational design of photocatalyst materials.
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Affiliation(s)
- Ilan Jen-La Plante
- †Department of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beersheva, Israel, 84105
| | - Ayelet Teitelboim
- ‡Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel, 76100
| | - Iddo Pinkas
- §Department of Chemical Research Support, Weizmann Institute of Science, Rehovot, Israel 76100
| | - Dan Oron
- ‡Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot, Israel, 76100
| | - Taleb Mokari
- †Department of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beersheva, Israel, 84105
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35
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Jiang L, Yuan L, Cao L, Nijhuis CA. Controlling leakage currents: the role of the binding group and purity of the precursors for self-assembled monolayers in the performance of molecular diodes. J Am Chem Soc 2014; 136:1982-91. [PMID: 24401113 DOI: 10.1021/ja411116n] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
This paper describes that the performance of molecular diodes based on self-assembled monolayers (SAMs) depends on the type of anchoring group and purity of the precursors of these SAMs. The SAMs were formed on ultrasmooth template-stripped silver (Ag(TS)) surfaces, which served as the bottom-electrode, and a eutectic alloy of gallium-indium was used as the top-electrode. When these junctions incorporate SAMs of the form S(CH2)11Fc (≡ SC11Fc) derived from HSC11Fc, they are good molecular diodes and rectify currents with rectification ratios R (≡ |J(-1.0 V)|/|J(+1.0 V)|) of ∼1.0 × 10(2). Replacing the thiol by disulfide or thioacetate functionalities in the precursor resulted in molecular diodes with values of R close to unity. Cyclic voltammetry and angle resolved X-ray photoelectron spectroscopy indicated that the SAMs derived from the disulfide or thioacetate precursors have lower surface coverages and are more defective than SAMs derived from thiols. In the junctions these defective SAMs caused defects and increased the leakage currents. The purity of the thiol-precursor is also crucial: 3 or 5% of disulfide present in the thiol caused a 28 or 61% decrease in R, respectively, and >15% of disulfide lowered R to unity, while the yield in nonshorting junctions remained unchanged. Our results show that the type of binding group, and the puritiy of the thiols, are crucial parameters in the experimental design of molecular electronic devices to ensure optimal device performance by keeping leakage currents to a minimum.
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Affiliation(s)
- Li Jiang
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543
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36
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Ryan KM, Singh S, Liu P, Singh A. Assembly of binary, ternary and quaternary compound semiconductor nanorods: From local to device scale ordering influenced by surface charge. CrystEngComm 2014. [DOI: 10.1039/c4ce00679h] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this article we outline the assembly of binary, ternary and quaternary nanorods using three separate protocols: (a) droplet based assembly, (b) assembly in a vial, (c) electrophoretic deposition. The rods are the important photoabsorbers CdS, CdSexS1−x, CuInxGa1−xS, and Cu2ZnSnS4.
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Affiliation(s)
- Kevin M. Ryan
- Materials and Surface Science Institute and Department of Chemical and Environmental Sciences
- University of Limerick
- Limerick, Ireland
| | - Shalini Singh
- Materials and Surface Science Institute and Department of Chemical and Environmental Sciences
- University of Limerick
- Limerick, Ireland
| | - Pai Liu
- Materials and Surface Science Institute and Department of Chemical and Environmental Sciences
- University of Limerick
- Limerick, Ireland
| | - Ajay Singh
- The Molecular Foundry
- Lawrence Berkeley National Laboratory
- Berkeley, USA
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37
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Upadhyay AP, Behara DK, Sharma GP, Bajpai A, Sharac N, Ragan R, Pala RGS, Sivakumar S. Generic process for highly stable metallic nanoparticle-semiconductor heterostructures via click chemistry for electro/photocatalytic applications. ACS APPLIED MATERIALS & INTERFACES 2013; 5:9554-9562. [PMID: 24018108 DOI: 10.1021/am402398h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Metallic nanoparticles (MNP) are utilized as electrocatalysts, cocatalysts, and photon absorbers in heterostructures that harvest solar energy. In such systems, the interface formed should be stable over a wide range of pH values and electrolytes. Many current nonthermal processing strategies rely on physical interactions to bind the MNP to the semiconductor. In this work, we demonstrate a generic chemical approach for fabricating highly stable electrochemically/photocatalytically active monolayers and tailored multilayered nanoparticle structures using azide/alkyne-modified Au, TiO2, and SiO2 nanoparticles on alkyne/azide-modified silicon, indium tin oxide, titania, stainless steel, and glass substrates via click chemistry. The stability, electrical, electrochemical, and photocatalytic properties of the interface are shown via electrochemical water splitting, methanol oxidation, and photocatalytic degradation of Rhodamine B (RhB) dye. The results suggest that the proposed approach can be extended for the large-scale fabrication of highly stable heterostructure materials for electrochemical and photoelectrocatalytic devices.
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Affiliation(s)
- Arun Prakash Upadhyay
- Department of Chemical Engineering, Indian Institute of Technology Kanpur , Kanpur, Uttar Pradesh 208016, India
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38
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Hartmann L, Djurado D, Florea I, Legrand JF, Fiore A, Reiss P, Doyle S, Vorobiev A, Pouget S, Chandezon F, Ersen O, Brinkmann M. Large-Scale Simultaneous Orientation of CdSe Nanorods and Regioregular Poly(3-hexylthiophene) by Mechanical Rubbing. Macromolecules 2013. [DOI: 10.1021/ma400880x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Lucia Hartmann
- ICS (UPR22-CNRS), 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France
- UMR SPrAM 5819 (CEA-CNRS-UJF) and SP2M, CEA Grenoble/INAC, 38054 Grenoble
Cedex, France
| | - David Djurado
- UMR SPrAM 5819 (CEA-CNRS-UJF) and SP2M, CEA Grenoble/INAC, 38054 Grenoble
Cedex, France
| | - Ileana Florea
- IPCMS (UMR 7504 CNRS − Université de Strasbourg), 23 rue du
Loess, BP 43, 67034 Strasbourg Cedex 2, France
| | | | - Angela Fiore
- UMR SPrAM 5819 (CEA-CNRS-UJF) and SP2M, CEA Grenoble/INAC, 38054 Grenoble
Cedex, France
| | - Peter Reiss
- UMR SPrAM 5819 (CEA-CNRS-UJF) and SP2M, CEA Grenoble/INAC, 38054 Grenoble
Cedex, France
| | - Stephen Doyle
- Institut für Synchrotronstrahlung (ISS), Hermann-von-Helmholtz-Platz
1, D-76344 Eggenstein-Leopoldshafen, Germany
| | - Alexeï Vorobiev
- ESRF, 6 rue J. Horovitz,
BP220, 38043 Grenoble Cedex 9, France
| | - Stéphanie Pouget
- UMR SPrAM 5819 (CEA-CNRS-UJF) and SP2M, CEA Grenoble/INAC, 38054 Grenoble
Cedex, France
| | - Frédéric Chandezon
- UMR SPrAM 5819 (CEA-CNRS-UJF) and SP2M, CEA Grenoble/INAC, 38054 Grenoble
Cedex, France
| | - Ovidiu Ersen
- IPCMS (UMR 7504 CNRS − Université de Strasbourg), 23 rue du
Loess, BP 43, 67034 Strasbourg Cedex 2, France
| | - Martin Brinkmann
- ICS (UPR22-CNRS), 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2, France
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39
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De Trizio L, De Donato F, Casu A, Genovese A, Falqui A, Povia M, Manna L. Colloidal CdSe/Cu3P/CdSe nanocrystal heterostructures and their evolution upon thermal annealing. ACS NANO 2013; 7:3997-4005. [PMID: 23557168 DOI: 10.1021/nn3060219] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We report the synthesis of colloidal CdSe/Cu(3)P/CdSe nanocrystal heterostructures grown from hexagonal Cu(3)P platelets as templates. One type of heterostructure was a sort of "coral", formed by vertical pillars of CdSe grown preferentially on both basal facets of a Cu(3)P platelet and at its edges. Another type of heterostructure had a "sandwich" type of architecture, formed by two thick, epitaxial CdSe layers encasing the original Cu(3)P platelet. When the sandwiches were annealed under vacuum up to 450 °C, sublimation of P and Cd species with concomitant interdiffusion of Cu and Se species was observed by in situ HR- and EFTEM analyses. These processes transformed the starting sandwiches into Cu2Se nanoplatelets. Under the same conditions, both the pristine (uncoated) Cu(3)P platelets and a control sample made of isolated CdSe nanocrystals were stable. Therefore, the thermal instability of the sandwiches under vacuum might be explained by the diffusion of Cu species from Cu(3)P cores into CdSe domains, which triggered sublimation of Cd, as well as out-diffusion of P species and their partial sublimation, together with the overall transformation of the sandwiches into Cu(2)Se nanocrystals. A similar fate was followed by the coral-like structures. These CdSe/Cu(3)P/CdSe nanocrystals are therefore an example of a nanostructure that is thermally unstable, despite its separate components showing to be stable under the same conditions.
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Affiliation(s)
- Luca De Trizio
- Department of Nanochemistry, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
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40
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Song N, Zhu H, Liu Z, Huang Z, Wu D, Lian T. Unraveling the exciton quenching mechanism of quantum dots on antimony-doped SnO₂ films by transient absorption and single dot fluorescence spectroscopy. ACS NANO 2013; 7:1599-1608. [PMID: 23281781 DOI: 10.1021/nn3054494] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Integrating quantum dots (QDs) into modern optoelectronic devices requires an understanding of how a transparent conducting substrate affects the properties of QDs, especially their excited-state dynamics. Here, the exciton quenching dynamics of core/multishell (CdSe/CdS(3ML)ZnCdS(2ML)ZnS(2ML)) quantum dots deposited on glass, tin oxide (SnO₂), and antimony (Sb)-doped tin oxide (ATO) films are studied by transient absorption and single QD fluorescence spectroscopic methods. By comparing ensemble-averaged fluorescence decay and transient absorption kinetics, we show that, for QDs on SnO₂, the exciton is quenched by electron transfer from the QD to SnO₂. At the QD-ATO interface, much faster exciton quenching rates are observed and attributed to fast Auger recombination in charged QDs formed by Fermi level equilibration between the QD and n-doped ATO. Single QDs on SnO₂ and ATO show similar blinking dynamics with correlated fluctuations of emission intensities and lifetimes. Compared to QDs on SnO₂, QDs on ATO films show larger variation of average exciton quenching rates, which is attributed to a broad distribution of the number of charges and nature of charging sites on the QD surface.
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Affiliation(s)
- Nianhui Song
- Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA
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41
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Sytnyk M, Kirchschlager R, Bodnarchuk MI, Primetzhofer D, Kriegner D, Enser H, Stangl J, Bauer P, Voith M, Hassel AW, Krumeich F, Ludwig F, Meingast A, Kothleitner G, Kovalenko MV, Heiss W. Tuning the magnetic properties of metal oxide nanocrystal heterostructures by cation exchange. NANO LETTERS 2013; 13:586-93. [PMID: 23362940 PMCID: PMC3573734 DOI: 10.1021/nl304115r] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 01/26/2013] [Indexed: 05/15/2023]
Abstract
For three types of colloidal magnetic nanocrystals, we demonstrate that postsynthetic cation exchange enables tuning of the nanocrystal's magnetic properties and achieving characteristics not obtainable by conventional synthetic routes. While the cation exchange procedure, performed in solution phase approach, was restricted so far to chalcogenide based semiconductor nanocrystals, here ferrite-based nanocrystals were subjected to a Fe(2+) to Co(2+) cation exchange procedure. This allows tracing of the compositional modifications by systematic and detailed magnetic characterization. In homogeneous magnetite nanocrystals and in gold/magnetite core shell nanocrystals the cation exchange increases the coercivity field, the remanence magnetization, as well as the superparamagnetic blocking temperature. For core/shell nanoheterostructures a selective doping of either the shell or predominantly of the core with Co(2+) is demonstrated. By applying the cation exchange to FeO/CoFe(2)O(4) core/shell nanocrystals the Neél temperature of the core material is increased and exchange-bias effects are enhanced so that vertical shifts of the hysteresis loops are obtained which are superior to those in any other system.
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Affiliation(s)
- Mykhailo Sytnyk
- Institute of Semiconductor and
Solid State Physics, University Linz, Altenbergerstraße
69, 4040 Linz, Austria
| | - Raimund Kirchschlager
- Institute of Semiconductor and
Solid State Physics, University Linz, Altenbergerstraße
69, 4040 Linz, Austria
| | - Maryna I. Bodnarchuk
- Institute of Inorganic Chemistry,
Department of Chemistry and Applied Biosciences, ETH
Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and
Photovoltaics, EMPA-Swiss Federal Laboratories for Materials
Science and Technology, CH-8060, Switzerland
| | - Daniel Primetzhofer
- Ion physics, Department of Physics
and Astronomy, Uppsala University, 75120
Uppsala, Sweden
| | - Dominik Kriegner
- Institute of Semiconductor and
Solid State Physics, University Linz, Altenbergerstraße
69, 4040 Linz, Austria
| | - Herbert Enser
- Institute of Semiconductor and
Solid State Physics, University Linz, Altenbergerstraße
69, 4040 Linz, Austria
| | - Julian Stangl
- Institute of Semiconductor and
Solid State Physics, University Linz, Altenbergerstraße
69, 4040 Linz, Austria
| | - Peter Bauer
- Institute
of Experimental Physics, University Linz, 4040 Linz, Austria
| | - Michael Voith
- Institute
for Chemical Technology
of Inorganic Materials, University Linz, 4040 Linz, Austria
| | - Achim Walter Hassel
- Institute
for Chemical Technology
of Inorganic Materials, University Linz, 4040 Linz, Austria
| | - Frank Krumeich
- Institute of Inorganic Chemistry,
Department of Chemistry and Applied Biosciences, ETH
Zurich, CH-8093, Switzerland
| | - Frank Ludwig
- Institut
für Elektrische Messtechnik
und Grundlagen der Elektrotechnik, TU Braunschweig, 38106 Braunschweig, Germany
| | - Arno Meingast
- Austrian Centre for Electron
Microscopy and Nanoanalysis, Institute for Electron Microscopy, Graz University of Technology, 8010 Graz, Austria
| | - Gerald Kothleitner
- Austrian Centre for Electron
Microscopy and Nanoanalysis, Institute for Electron Microscopy, Graz University of Technology, 8010 Graz, Austria
| | - Maksym V. Kovalenko
- Institute of Inorganic Chemistry,
Department of Chemistry and Applied Biosciences, ETH
Zurich, CH-8093, Switzerland
- Laboratory for Thin Films and
Photovoltaics, EMPA-Swiss Federal Laboratories for Materials
Science and Technology, CH-8060, Switzerland
| | - Wolfgang Heiss
- Institute of Semiconductor and
Solid State Physics, University Linz, Altenbergerstraße
69, 4040 Linz, Austria
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42
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Smith BD, Kirby DJ, Rivera IO, Keating CD. Self-assembly of segmented anisotropic particles: tuning compositional anisotropy to form vertical or horizontal arrays. ACS NANO 2013; 7:825-833. [PMID: 23244212 DOI: 10.1021/nn305394s] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Columnar arrays of anisotropic nano- and microparticles, in which the long axes of the particles are oriented perpendicular to the substrate, are of interest for photovoltaics and other applications. Array assembly typically requires applied electric or magnetic fields and/or controlled drying, which are challenging over large areas. Here, we describe a scalable approach to self-assemble multicomponent nanowires into columnar arrays. Self-assembly of partially etched nanowires (PENs) occurred spontaneously during sedimentation from suspension, without drying or applied fields. PENs, which have segments that are either gold or "empty" (solvent-filled) surrounded by a silica shell, were produced from striped metal nanowires by first coating with silica and then removing sacrificial segments by acid etching. Electrostatic repulsion between the particles was necessary for array assembly; however, details of PEN surface chemistry were relatively unimportant. The aspect ratio and relative center of mass (COM) of the PENs were important for determining whether the PEN long axes were vertically or horizontally aligned with respect to the underlying substrate. Arrays with predominantly vertically aligned particles were achieved for PENs with a large offset in COM relative to the geometric center, while other types of PENs formed horizontal arrays. Assemblies were formed over >10 cm(2) areas, with over 60% of particles standing. We assessed array uniformity and reproducibility by imaging many positions within each sample and performing multiple assemblies of differently segmented PENs. This work demonstrates the versatility of gravity-driven PEN array assembly and provides a framework for designing other anisotropic particle systems that self-assemble into columnar arrays.
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Affiliation(s)
- Benjamin D Smith
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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43
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Pietra F, Rabouw FT, Evers WH, Byelov DV, Petukhov AV, de Mello Donegá C, Vanmaekelbergh D. Semiconductor nanorod self-assembly at the liquid/air interface studied by in situ GISAXS and ex situ TEM. NANO LETTERS 2012; 12:5515-5523. [PMID: 23038984 DOI: 10.1021/nl302360u] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We study the self-assembly of colloidal CdSe/CdS nanorods (NRs) at the liquid/air interface combining time-resolved in situ grazing-incidence small angle X-ray scattering (GISAXS) and ex situ transmission electron microscopy (TEM). Our study shows that NR superstructure formation occurs at the liquid/air interface. Short NRs self-assemble into micrometers long tracks of NRs lying side by side flat on the surface. In contrast, longer NRs align vertically into ordered superstructures. Systematic variation of the NR length and initial concentration of the NR dispersion allowed us to tune the orientation of the NRs in the final superstructure. With GISAXS, we were able to follow the dynamics of the self-assembly. We propose a model of hierarchical self-organization that provides a basis for the understanding of the length-dependent self-organization of NRs at the liquid/air interface. This opens the way to new materials based on NR membranes and anisotropic thin films.
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Affiliation(s)
- Francesca Pietra
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Princetonplein 1, 3584 CC Utrecht, The Netherlands
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44
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Singh A, English NJ, Ryan KM. Highly Ordered Nanorod Assemblies Extending over Device Scale Areas and in Controlled Multilayers by Electrophoretic Deposition. J Phys Chem B 2012; 117:1608-15. [DOI: 10.1021/jp305184n] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Ajay Singh
- Materials
and Surface Science
Institute and Department of Chemical and Environmental Sciences, University of Limerick, Limerick, Ireland
- SFI-Strategic Research Cluster
in Solar Energy Research, University of Limerick, Limerick, Ireland
| | - Niall J. English
- UCD School of Chemical and Bioprocess
Engineering and Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
| | - Kevin M. Ryan
- Materials
and Surface Science
Institute and Department of Chemical and Environmental Sciences, University of Limerick, Limerick, Ireland
- SFI-Strategic Research Cluster
in Solar Energy Research, University of Limerick, Limerick, Ireland
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Rivest JB, Jain PK. Cation exchange on the nanoscale: an emerging technique for new material synthesis, device fabrication, and chemical sensing. Chem Soc Rev 2012; 42:89-96. [PMID: 22968228 DOI: 10.1039/c2cs35241a] [Citation(s) in RCA: 270] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cation exchange is an age-old technique for the chemical conversion of liquids or extended solids by place-exchanging the cations in an ionic material with a different set of cations. The technique is undergoing a major revival with the advent of high-quality nanocrystals: researchers are now able to overcome the limitations in bulk systems and fully exploit cation exchange for materials synthesis and discovery via rapid, low-temperature transformations in the solid state. In this tutorial review, we discuss cation exchange as a promising materials synthesis and discovery tool. Exchange on the nanoscale exhibits some unique attributes: rapid kinetics at room temperature (orders of magnitude faster than in the bulk) and the tuning of reactivity via control of nanocrystal size, shape, and surface faceting. These features make cation exchange a convenient tool for accessing nanocrystal compositions and morphologies for which conventional synthesis may not be established. A simple exchange reaction allows extension of nanochemistry to a larger part of the periodic table, beyond the typical gamut of II-VI, IV-VI, and III-V materials. Cation exchange transformations in nanocrystals can be topotactic and size- and shape-conserving, allowing nanocrystals synthesized by conventional methods to be used as templates for production of compositionally novel, multicomponent, or doped nanocrystals. Since phases and compositions resulting from an exchange reaction can be kinetically controlled, rather than governed by the phase diagram, nanocrystals of metastable and hitherto inaccessible compositions are attainable. Outside of materials synthesis, applications for cation exchange exist in water purification, chemical staining, and sensing. Since nanoscale cation exchange occurs rapidly at room temperature, it can be integrated with sensitive environments such as those in biological systems. Cation exchange is already allowing access to a variety of new materials and processes. With better mechanistic understanding and control, researchers may be able to advance the field to a stage where a custom nanostructure of arbitrary complexity would be achievable by simple cation exchange chemistry and a basic understanding of the periodic table.
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Affiliation(s)
- Jessy B Rivest
- The Molecular Foundry, Materials Science Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA
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Singh A, Coughlan C, Laffir F, Ryan KM. Assembly of CuIn(1-x)Ga(x)S2 nanorods into highly ordered 2D and 3D superstructures. ACS NANO 2012; 6:6977-6983. [PMID: 22765274 DOI: 10.1021/nn301999b] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Here, we report self- and directed assembly of CuIn(1-x)Ga(x)S(2) (CIGS) nanorods into highly ordered 2D and 3D superstructures. The assembly protocol is dictated by the ligand environment and is hence chemically tunable. Thiol capped nanorods spontaneously assemble into 3D aligned nanorod clusters over a period of hours with end to end and side to side order. These clusters can be disassembled by ligand exchange with an amine and subsequently reassembled either at a substrate interface or as free floating 2D sheets by directed assembly protocols. This dimensional control of CIGS nanorod assembly, extending over device scale areas with high degrees of order, is highly attractive for applications utilizing these important quaternary photoabsorbers.
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Affiliation(s)
- Ajay Singh
- Materials and Surface Science Institute and Department of Chemical and Environmental Sciences,University of Limerick, Limerick, Ireland
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Han SK, Gong M, Yao HB, Wang ZM, Yu SH. One-Pot Controlled Synthesis of Hexagonal-Prismatic Cu1.94S-ZnS, Cu1.94S-ZnS-Cu1.94S, and Cu1.94S-ZnS-Cu1.94S-ZnS-Cu1.94S Heteronanostructures. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201202128] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Han SK, Gong M, Yao HB, Wang ZM, Yu SH. One-Pot Controlled Synthesis of Hexagonal-Prismatic Cu1.94S-ZnS, Cu1.94S-ZnS-Cu1.94S, and Cu1.94S-ZnS-Cu1.94S-ZnS-Cu1.94S Heteronanostructures. Angew Chem Int Ed Engl 2012; 51:6365-8. [DOI: 10.1002/anie.201202128] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Indexed: 11/05/2022]
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Gasparotto A, Barreca D, Maccato C, Tondello E. Manufacturing of inorganic nanomaterials: concepts and perspectives. NANOSCALE 2012; 4:2813-2825. [PMID: 22434486 DOI: 10.1039/c2nr12083f] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The present paper aims at extracting key physical and chemical concepts for the development of inorganic nanomaterials with controlled size, shape, and topology. In particular, efforts are made to identify general guiding principles for the rational design of 0D, 1D, 2D and 3D architectures, focusing on selected model systems as representative case studies. To this aim, different strategies and approaches are discussed, in an attempt to unify concepts and ideas common to solid-, liquid- and gas-phase synthetic routes. Furthermore, the importance of tailoring the nanomaterial composition, structure and morphology is also highlighted in relation to their eventual technological applications.
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Affiliation(s)
- Alberto Gasparotto
- Department of Chemistry, Padova University and INSTM, Via Marzolo 1, 35131 Padova, Italy.
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Singh A, Dickinson C, Ryan KM. Insight into the 3D architecture and quasicrystal symmetry of multilayer nanorod assemblies from Moiré interference patterns. ACS NANO 2012; 6:3339-3345. [PMID: 22409442 DOI: 10.1021/nn300331x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Vertical nanorod assembly over three dimensions is shown to result in the formation of Moiré interference patterns arising from rotational offsets between respective monolayer sheets. Six distinct patterns are observed in HRTEM and angular dark-field STEM (DF-STEM) images, allowing the exact angle of rotation to be determined from their respective size and repeat order. At large rotation angles approaching 30°, the aperiodicity in the structure of the nanorod supercrystals becomes apparent, resulting in 12-fold ordering characteristics of a quasicrystal. The rotational offsets are further elucidated from Fourier transform and small angle electron diffraction, allowing interpretation of several multilayers when combined with DF-STEM and SEM. Pattern formation owing to angular rotation is differentiated from those occurring from a lateral shift, providing an important insight into the complex multilayered structures in assembled rods that may have an impact on their collective electronic or photonic properties. We also show how random tetrapods when present at low concentrations in colloidal nanorod solutions act as termination points for 2D sheet crystallization, impacting the size and shape of the resultant assemblies. The occurrence of Moiré patterns in rod assemblies demonstrates the extraordinary order achievable in their assembly and offers a nondestructive technique to precisely map the placement of each nanorod in this important nanoarchitecture.
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Affiliation(s)
- Ajay Singh
- Materials and Surface Science Institute and Department of Chemical and Environmental Sciences, University of Limerick, Limerick, Ireland
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