1
|
Wan S, Xiao S, Li M, Wang X, Lim KH, Hong M, Ibáñez M, Cabot A, Liu Y. Band Engineering Through Pb-Doping of Nanocrystal Building Blocks to Enhance Thermoelectric Performance in Cu 3SbSe 4. SMALL METHODS 2024; 8:e2301377. [PMID: 38152986 DOI: 10.1002/smtd.202301377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/29/2023] [Indexed: 12/29/2023]
Abstract
Developing cost-effective and high-performance thermoelectric (TE) materials to assemble efficient TE devices presents a multitude of challenges and opportunities. Cu3SbSe4 is a promising p-type TE material based on relatively earth abundant elements. However, the challenge lies in its poor electrical conductivity. Herein, an efficient and scalable solution-based approach is developed to synthesize high-quality Cu3SbSe4 nanocrystals doped with Pb at the Sb site. After ligand displacement and annealing treatments, the dried powders are consolidated into dense pellets, and their TE properties are investigated. Pb doping effectively increases the charge carrier concentration, resulting in a significant increase in electrical conductivity, while the Seebeck coefficients remain consistently high. The calculated band structure shows that Pb doping induces band convergence, thereby increasing the effective mass. Furthermore, the large ionic radius of Pb2+ results in the generation of additional point and plane defects and interphases, dramatically enhancing phonon scattering, which significantly decreases the lattice thermal conductivity at high temperatures. Overall, a maximum figure of merit (zTmax) ≈ 0.85 at 653 K is obtained in Cu3Sb0.97Pb0.03Se4. This represents a 1.6-fold increase compared to the undoped sample and exceeds most doped Cu3SbSe4-based materials produced by solid-state, demonstrating advantages of versatility and cost-effectiveness using a solution-based technology.
Collapse
Affiliation(s)
- Shanhong Wan
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei, 230009, P. R. China
| | - Shanshan Xiao
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei, 230009, P. R. China
| | - Mingquan Li
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei, 230009, P. R. China
| | - Xin Wang
- Center of Analysis and Test, Jiangsu University, Zhenjiang, 212013, P. R. China
| | - Khak Ho Lim
- Institute of Zhejiang University-Quzhou, 99 Zheda Rd, Quzhou, 324000, P. R. China
| | - Min Hong
- Centre for Future Materials, and School of Engineering, University of Southern Queensland, Springfield Central, Queensland, 4300, Australia
| | - Maria Ibáñez
- IST Austria, Am Campus 1, Klosterneuburg, 3400, Austria
| | - Andreu Cabot
- Catalonia Institute for Energy Research-IREC, Sant Adrià de Besòs, Barcelona, 08930, Spain
- Institució Catalana de Recerca i Estudis Avançats - ICREA, Barcelona, 08010, Spain
| | - Yu Liu
- Anhui Province Key Laboratory of Advanced Catalytic Materials and Reaction Engineering School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei, 230009, P. R. China
| |
Collapse
|
2
|
Liang JN, Tong H, Zeng YJ, Zhou WX. Machine learning assisted understanding of the layer-thickness dependent thermal conductivity in fluorinated graphene. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:415001. [PMID: 38976978 DOI: 10.1088/1361-648x/ad6050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Accepted: 07/08/2024] [Indexed: 07/10/2024]
Abstract
Manipulating thermal conductivity (κ) plays vital role in high-performance thermoelectric conversion, thermal insulation and thermal management devices. In this work, we using the machine learning-based interatomic potential and the phonon Boltzmann transport equation to systematically investigate layer thickness dependentκof fluorinated graphene (FG). We show that the latticeκof FG can be significantly decreased with Bernal bilayer stacking. Surprisingly, the further increasing of stacking layer can no longer affect theκ, however, theκis increased in the bulk configuration. The variation ofκcan be attributed to the crystal symmetry change from P-3m1 (164) at single layer to P3m1 (156) at multilayer. The decreasing crystal symmetry from single layer to bilayer resulting stronger phonon scattering and thus leading a lowerκ. Moreover, we also show that the contribution of acoustic mode toκdecreases with the increase of layers, while the contribution of optical mode toκis increased with increasing layers. These results provide a further understanding for the phonon scattering mechanism of layer thickness dependentκ.
Collapse
Affiliation(s)
- Jun-Nan Liang
- School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan 411201, People's Republic of China
| | - Hua Tong
- School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan 411201, People's Republic of China
| | - Yu-Jia Zeng
- School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan 411201, People's Republic of China
| | - Wu-Xing Zhou
- School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan 411201, People's Republic of China
| |
Collapse
|
3
|
Hoat DM, Dien VK, Ho QD, Dam DP, Tien NT, Nguyen DK. Rich essential properties of silicon-substituted graphene nanoribbons: a comprehensive computational study. Phys Chem Chem Phys 2024; 26:15939-15956. [PMID: 38691388 DOI: 10.1039/d4cp00290c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
The diverse structural, electronic, and magnetic properties of silicon (Si)-substituted armchair and zigzag graphene nanoribbons (AGNRs and ZGNRs) were investigated using spin-polarized density functional theory (DFT) calculations. Pristine AGNRs belong to a nonmagnetic semiconductor with a direct bandgap of 1.63/1.92 eV determined by PBE/HSE06 functionals. Under various Si substitutions, nonmagnetic bandgaps were tuned at 1.49/1.87, 1.06/1.84, 0.81/1.45, 1.04/1.71, 0.89/1.05, and 2.38/3.0 eV (PBE/HSE06) in the single Si edge-, single Si non-edge-, double Si ortho-, double Si meta-, double Si para-, and 100% Si-substituted AGNR configurations, respectively. Meanwhile, pristine ZGNRs displayed antiferromagnetic semiconducting behavior with a spin degenerate bandgap of 0.52/0.81 eV (PBE/HSE06) and becomes a ferromagnetic semimetal in the single Si configurations or an unusual ferromagnetic semiconductor in the 100% Si configuration. Under the developed first-principles theoretical framework, the formation of quasi π (C-2pz and Si-3pz) and quasi σ (C-2s, -2pxy and Si-3s and -3pxy) bands was identified in the Si-substituted configurations. These quasi π and quasi σ bands showed weak separation, resulting in weak quasi sp2 hybridization in Si-C bonds, in which the identified hybridization mechanism was a strong evidence for the formation of stable planar 1D structures in the Si-substituted configurations. Our complete revelation of the essential properties of Si-substituted GNRs can provide a complete understanding of their chemically doped 1D materials for various practical applications.
Collapse
Affiliation(s)
- D M Hoat
- Institute of Theoretical and Applied Research, Duy Tan University, Ha Noi 100000, Vietnam
- Faculty of Natural Sciences, Duy Tan University, Da Nang 550000, Vietnam
| | - Vo Khuong Dien
- Division of Applied Physics, Dong Nai Technology University, Bien Hoa City, Vietnam.
- Faculty of Engineering, Dong Nai Technology University, Bien Hoa City, Vietnam
| | - Quoc Duy Ho
- Department of Mathematics and Physics, Universitetet i Stavanger, Stavanger, Norway
| | - Dang Phuc Dam
- College of Natural Sciences, Can Tho University, Can Tho City 900000, Vietnam
| | - Nguyen Thanh Tien
- College of Natural Sciences, Can Tho University, Can Tho City 900000, Vietnam
| | - Duy Khanh Nguyen
- Laboratory for Computational Physics, Institute for Computational Science and Artificial Intelligence, Van Lang University, Ho Chi Minh City, Vietnam.
- Faculty of Mechanical - Electrical and Computer Engineering, School of Technology, Van Lang University, Ho Chi Minh City, Vietnam
| |
Collapse
|
4
|
Sikorska C, Vincent E, Schnepf A, Gaston N. Tuning the electronic structure of gold cluster-assembled materials by altering organophosphine ligands. Phys Chem Chem Phys 2024; 26:10673-10687. [PMID: 38511629 DOI: 10.1039/d3cp04027e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Superatomic clusters can be assembled to build bulk matter, where the individual characteristics are preserved. The main benefit of these materials over conventional bulk species is the capability to tailor their features by altering the physicochemical identities of individual clusters. Electronic properties of metal clusters can be modified by a protective shell of ligands that attach to the surface and make the whole nanoparticle soluble in organic or aqueous solvents. In the present work, we demonstrate that properly chosen ligands provide not only steric protection from aggregation but also tune the redox activity of metal clusters. We investigate the role of the ligands in electronic structure tunability and ligand-field splitting. Our first-principles calculations agree with the experiments, showing that phosphine-protected gold materials are small gap semiconductors. The obtained bandgaps strongly depend on the ligand used. Hence, using phosphine and organophosphine ligands should be feasible and promising while designing the novel superatom-based materials since the desired range of the bandgap might be achieved (by the proper choice of the ligand).
Collapse
Affiliation(s)
- Celina Sikorska
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Physics, The University of Auckland, 38 Princes Street, Auckland 1010, New Zealand.
- Faculty of Chemistry, University of Gdanśk, Fahrenheit Union of Universities in Gdanśk, 80-308 Gdanśk, Poland
| | - Emma Vincent
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Physics, The University of Auckland, 38 Princes Street, Auckland 1010, New Zealand.
| | - Andreas Schnepf
- Institut für Anorganische Chemie Universität Tübingen, Auf der Morgenstelle 18, D-72076 Tübingen, Germany
| | - Nicola Gaston
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Physics, The University of Auckland, 38 Princes Street, Auckland 1010, New Zealand.
| |
Collapse
|
5
|
Sikorska C. Design and Investigation of Superatoms for Redox Applications: First-Principles Studies. MICROMACHINES 2023; 15:78. [PMID: 38258197 PMCID: PMC10820084 DOI: 10.3390/mi15010078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/24/2024]
Abstract
A superatom is a cluster of atoms that acts like a single atom. Two main groups of superatoms are superalkalis and superhalogens, which mimic the chemistry of alkali and halogen atoms, respectively. The ionization energies of superalkalis are smaller than those of alkalis (<3.89 eV for cesium atom), and the electron affinities of superhalogens are larger than that of halogens (>3.61 eV for chlorine atom). Exploring new superalkali/superhalogen aims to provide reliable data and predictions of the use of such compounds as redox agents in the reduction/oxidation of counterpart systems, as well as the role they can play more generally in materials science. The low ionization energies of superalkalis make them candidates for catalysts for CO2 conversion into renewable fuels and value-added chemicals. The large electron affinity of superhalogens makes them strong oxidizing agents for bonding and removing toxic molecules from the environment. By using the superatoms as building blocks of cluster-assembled materials, we can achieve the functional features of atom-based materials (like conductivity or catalytic potential) while having more flexibility to achieve higher performance. This feature paper covers the issues of designing such compounds and demonstrates how modifications of the superatoms (superhalogens and superalkalis) allow for the tuning of the electronic structure and might be used to create unique functional materials. The designed superatoms can form stable perovskites for solar cells, electrolytes for Li-ion batteries of electric vehicles, superatomic solids, and semiconducting materials. The designed superatoms and their redox potential evaluation could help experimentalists create new materials for use in fields such as energy storage and climate change.
Collapse
Affiliation(s)
- Celina Sikorska
- Faculty of Chemistry, University of Gdańsk, Fahrenheit Union of Universities in Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland;
- Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| |
Collapse
|
6
|
Yu Y, He Y, Yan P, Wang S, Dong F. Boosted C-C coupling with Cu-Ag alloy sub-nanoclusters for CO 2-to-C 2H 4 photosynthesis. Proc Natl Acad Sci U S A 2023; 120:e2307320120. [PMID: 37871220 PMCID: PMC10622893 DOI: 10.1073/pnas.2307320120] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 09/07/2023] [Indexed: 10/25/2023] Open
Abstract
The selective photocatalytic conversion of CO2 and H2O to high value-added C2H4 remains a great challenge, mainly attributed to the difficulties in C-C coupling of reaction intermediates and desorption of C2H4* intermediates from the catalyst surface. These two key issues can be simultaneously overcome by alloying Ag with Cu which gives enhanced activity to both reactions. Herein, we developed a facile stepwise photodeposition strategy to load Cu-Ag alloy sub-nanoclusters (ASNCs) on TiO2 for CO2 photoreduction to produce C2H4. The optimized catalyst exhibits a record-high C2H4 formation rate (1110.6 ± 82.5 μmol g-1 h-1) with selectivity of 49.1 ± 1.9%, which is an order-of-magnitude enhancement relative to current work for C2H4 photosynthesis. The in situ FT-IR spectra combined with DFT calculations reveal the synergistic effect of Cu and Ag in Cu-Ag ASNCs, which enable an excellent C-C coupling capability like Ag and promoted C2H4* desorption property like Cu, thus advancing the selective and efficient production of C2H4. The present work provides a deeper understanding on cluster chemistry and C-C coupling mechanism for CO2 reduction on ASNCs and develops a feasible strategy for photoreduction CO2 to C2 fuels or industrial feedstocks.
Collapse
Affiliation(s)
- Yangyang Yu
- Research Center for Carbon-Neutral Environmental & Energy Technology, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu611731, China
- Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou313000, China
| | - Ye He
- School of Resources and Environment, University of Electronic Science and Technology of China, Chengdu611731, China
| | - Ping Yan
- Research Center for Carbon-Neutral Environmental & Energy Technology, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu611731, China
| | - Shengyao Wang
- College of Science, Huazhong Agricultural University, Wuhan430070, China
| | - Fan Dong
- Research Center for Carbon-Neutral Environmental & Energy Technology, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu611731, China
- Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou313000, China
| |
Collapse
|
7
|
Riemelmoser S, Verdi C, Kaltak M, Kresse G. Machine Learning Density Functionals from the Random-Phase Approximation. J Chem Theory Comput 2023; 19:7287-7299. [PMID: 37800677 PMCID: PMC10601474 DOI: 10.1021/acs.jctc.3c00848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Indexed: 10/07/2023]
Abstract
Kohn-Sham density functional theory (DFT) is the standard method for first-principles calculations in computational chemistry and materials science. More accurate theories such as the random-phase approximation (RPA) are limited in application due to their large computational cost. Here, we use machine learning to map the RPA to a pure Kohn-Sham density functional. The machine learned RPA model (ML-RPA) is a nonlocal extension of the standard gradient approximation. The density descriptors used as ingredients for the enhancement factor are nonlocal counterparts of the local density and its gradient. Rather than fitting only RPA exchange-correlation energies, we also include derivative information in the form of RPA optimized effective potentials. We train a single ML-RPA functional for diamond, its surfaces, and liquid water. The accuracy of ML-RPA for the formation energies of 28 diamond surfaces reaches that of state-of-the-art van der Waals functionals. For liquid water, however, ML-RPA cannot yet improve upon the standard gradient approximation. Overall, our work demonstrates how machine learning can extend the applicability of the RPA to larger system sizes, time scales, and chemical spaces.
Collapse
Affiliation(s)
- Stefan Riemelmoser
- Faculty
of Physics and Center for Computational Materials Science, University of Vienna, Kolingasse 14-16, A-1090 Vienna, Austria
- Vienna
Doctoral School in Physics, University of
Vienna, Boltzmanngasse
5, A-1090 Vienna, Austria
| | - Carla Verdi
- Faculty
of Physics and Center for Computational Materials Science, University of Vienna, Kolingasse 14-16, A-1090 Vienna, Austria
- School
of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia
- School
of Mathematics and Physics, The University
of Queensland, Brisbane, Queensland 4072, Australia
| | - Merzuk Kaltak
- VASP
Software GmbH, Sensengasse
8/12, A-1090 Vienna, Austria
| | - Georg Kresse
- Faculty
of Physics and Center for Computational Materials Science, University of Vienna, Kolingasse 14-16, A-1090 Vienna, Austria
- VASP
Software GmbH, Sensengasse
8/12, A-1090 Vienna, Austria
| |
Collapse
|
8
|
Wang J, Gao H, Han Y, Ding C, Pan S, Wang Y, Jia Q, Wang HT, Xing D, Sun J. MAGUS: machine learning and graph theory assisted universal structure searcher. Natl Sci Rev 2023; 10:nwad128. [PMID: 37332628 PMCID: PMC10275355 DOI: 10.1093/nsr/nwad128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/30/2023] [Accepted: 04/28/2023] [Indexed: 06/20/2023] Open
Abstract
Crystal structure predictions based on first-principles calculations have gained great success in materials science and solid state physics. However, the remaining challenges still limit their applications in systems with a large number of atoms, especially the complexity of conformational space and the cost of local optimizations for big systems. Here, we introduce a crystal structure prediction method, MAGUS, based on the evolutionary algorithm, which addresses the above challenges with machine learning and graph theory. Techniques used in the program are summarized in detail and benchmark tests are provided. With intensive tests, we demonstrate that on-the-fly machine-learning potentials can be used to significantly reduce the number of expensive first-principles calculations, and the crystal decomposition based on graph theory can efficiently decrease the required configurations in order to find the target structures. We also summarized the representative applications of this method on several research topics, including unexpected compounds in the interior of planets and their exotic states at high pressure and high temperature (superionic, plastic, partially diffusive state, etc.); new functional materials (superhard, high-energy-density, superconducting, photoelectric materials), etc. These successful applications demonstrated that MAGUS code can help to accelerate the discovery of interesting materials and phenomena, as well as the significant value of crystal structure predictions in general.
Collapse
Affiliation(s)
| | | | | | - Chi Ding
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Shuning Pan
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Yong Wang
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Qiuhan Jia
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Hui-Tian Wang
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Dingyu Xing
- National Laboratory of Solid State Microstructures, School of Physics and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | | |
Collapse
|
9
|
Sikorska C, Gaston N. Molecular crystals vs. superatomic lattice: a case study with superalkali-superhalogen compounds. Phys Chem Chem Phys 2022; 24:8763-8774. [PMID: 35352731 DOI: 10.1039/d1cp05761h] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Using a first-principles approach, we study the assembly of atomically-precise cluster solids with atomic precision. The aims are to create binary assemblies of clusters through charge transfer between neutral molecular clusters, and employing intercluster electrostatic attraction as a driving force for co-assembly. We combined pairs of complementary clusters in which one cluster is electron-donating (superalkali) and the other is electron-accepting (superhalogen). From the analysis of the binding energy between superatomic counterparts, charge transfer, and the relative size of the clusters, we analyze the resulting structures as either molecular crystals or superatomic lattices. We demonstrate that the substitution of a single atom can result in minor changes to the crystal structure of the binary solids or entirely new packing structures. The [N4Mg6Li]+[AlCl4]-, [N4Mg6Na]+[AlCl4]-, [N4Mg6K]+[AlCl4]-, [N4Mg6Li]+[AlF4]-, [N4Mg6Na]+[AlF4]-, and [N4Mg6K]+[AlF4]- compounds all form the same close-packed superatomic lattice structure through halogen bonding, with subtle differences in the orientation of the superatoms. These salts may also form molecular crystals where clusters are held to one another by electrostatic interactions. Our results emphasize how the structure of superatomic solids can be tuned upon single atom substitution.
Collapse
Affiliation(s)
- Celina Sikorska
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| | - Nicola Gaston
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| |
Collapse
|
10
|
Chen P, Dong X, Huang M, Li K, Xiao L, Sheng J, Chen S, Zhou Y, Dong F. Rapid Self-Decomposition of g-C 3N 4 During Gas–Solid Photocatalytic CO 2 Reduction and Its Effects on Performance Assessment. ACS Catal 2022. [DOI: 10.1021/acscatal.2c00815] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peng Chen
- Yangtze Delta Region Institute (Huzhou) & Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Huzhou 313000, China
- The Center of New Energy Materials and Technology, School of New Energy and Materials, Southwest Petroleum University, Chengdu 610500, China
| | - Xing’an Dong
- Yangtze Delta Region Institute (Huzhou) & Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Huzhou 313000, China
| | - Ming Huang
- Yangtze Delta Region Institute (Huzhou) & Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Huzhou 313000, China
| | - Kanglu Li
- Yangtze Delta Region Institute (Huzhou) & Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Huzhou 313000, China
| | - Lei Xiao
- Yangtze Delta Region Institute (Huzhou) & Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Huzhou 313000, China
| | - Jianping Sheng
- Yangtze Delta Region Institute (Huzhou) & Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Huzhou 313000, China
| | - Si Chen
- Yangtze Delta Region Institute (Huzhou) & Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Huzhou 313000, China
| | - Ying Zhou
- The Center of New Energy Materials and Technology, School of New Energy and Materials, Southwest Petroleum University, Chengdu 610500, China
| | - Fan Dong
- Yangtze Delta Region Institute (Huzhou) & Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Huzhou 313000, China
- The Center of New Energy Materials and Technology, School of New Energy and Materials, Southwest Petroleum University, Chengdu 610500, China
- State Centre for International Cooperation on Designer Low-Carbon and Environmental Materials (CDLCEM), School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
| |
Collapse
|
11
|
Sikorska C, Gaston N. Bimetallic superalkali substitution in the CsPbBr 3 perovskite: Pseudocubic phases and tunable bandgap. J Chem Phys 2021; 155:174307. [PMID: 34742223 DOI: 10.1063/5.0067708] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Perovskites attract attention as efficient light absorbers for solar cells due to their high-power conversion efficiency (up to 24%). The high photoelectric conversion efficiency is greatly affected by a suitable band structure. Cation substitution can be an effective approach to tune the electronic band structure of lead halide perovskites. In this work, superalkali cations were introduced to replace the Cs+ cation in the CsPbBr3 material. The bimetallic superalkalis (LiMg, NaMg, LiCa, and NaCa) were inserted since they are structurally simple systems and have a strong tendency to lose one electron to achieve a closed-shell cation. The cation substitution in the lead halide perovskite leads to changes in the shape of both valence and conduction bands compared to CsPbBr3. Introducing superalkali cations produces extra electronic states close to the Fermi level, which arise from the formation of alkali earth metal states at the top of the valence band. Our first-principles computations reveal that bimetallic superalkali substitution decreases the bandgap of the perovskite. The bandgaps of MgLi-PbBr3 (1.35 eV) and MgNa-PbBr3 (1.06 eV) are lower than the bandgap of CsPbBr3 (2.48 eV) and within the optimal bandgap (i.e., 1.1-1.4 eV) for single-junction solar cells. Thus, the MgLi-PbBr3 and MgNa-PbBr3 inorganic perovskites are promising candidates for high-efficiency solar cells.
Collapse
Affiliation(s)
- Celina Sikorska
- The MacDiarmid Institute of Advanced Materials and Nanotechnology, A New Zealand Centre of Research Excellence, Wellington, New Zealand
| | - Nicola Gaston
- The MacDiarmid Institute of Advanced Materials and Nanotechnology, A New Zealand Centre of Research Excellence, Wellington, New Zealand
| |
Collapse
|
12
|
Catalan FCI, Anh LT, Oh J, Kazuma E, Hayazawa N, Ikemiya N, Kamoshida N, Tateyama Y, Einaga Y, Kim Y. Localized Graphitization on Diamond Surface as a Manifestation of Dopants. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2103250. [PMID: 34487374 DOI: 10.1002/adma.202103250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 07/07/2021] [Indexed: 06/13/2023]
Abstract
Doped diamond electrodes have attracted significant attention for decades owing to their excellent physical and electrochemical properties. However, direct experimental observation of dopant effects on the diamond surface has not been available until now. Here, low-temperature scanning tunneling microscopy is utilized to investigate the atomic-scale morphology and electronic structures of (100)- and (111)-oriented boron-doped diamond (BDD) electrodes. Graphitized domains of a few nanometers are shown to manifest the effects of boron dopants on the BDD surface. Confirmed by first-principles calculations, local density of states measurements reveal that the electronic structure of these features is characterized by in-gap states induced by boron-related lattice deformation. The dopant-related graphitization is uniquely observed in BDD (111), which explains its electrochemical superiority over the (100) facet. These experimental observations provide atomic-scale information about the role of dopants in modulating the conductivity of diamond, as well as, possibly, other functional doped materials.
Collapse
Affiliation(s)
| | - Le The Anh
- Center for Green Research on Energy and Environmental Materials (GREEN) and International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Junepyo Oh
- Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Emiko Kazuma
- Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Norihiko Hayazawa
- Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| | - Norihito Ikemiya
- Department of Chemistry, Keio University, 3-14-1 Hiyoshi, Yokohama, 223-8522, Japan
| | - Naoki Kamoshida
- Department of Chemistry, Keio University, 3-14-1 Hiyoshi, Yokohama, 223-8522, Japan
| | - Yoshitaka Tateyama
- Center for Green Research on Energy and Environmental Materials (GREEN) and International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Yasuaki Einaga
- Department of Chemistry, Keio University, 3-14-1 Hiyoshi, Yokohama, 223-8522, Japan
| | - Yousoo Kim
- Surface and Interface Science Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan
| |
Collapse
|
13
|
Yang J, Liu X, Guo W. Nonmonotonous Distance Dependence of van der Waals Screening by a Dielectric Layer. J Phys Chem Lett 2021; 12:4993-4999. [PMID: 34015923 DOI: 10.1021/acs.jpclett.1c00870] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Van der Waals (vdW) screening or Faraday-cage-like screening of vdW interaction by monolayer crystals has recently been observed in experiments and understood from first-principles theories. Here, we investigate the vdW screening by a bulky dielectric layer using the Lifshitz theory. The ratio of vdW screening is found to depend on not only the interobject distance but also the thicknesses of the separated layers. Surprisingly, the screening ratio exhibits a nonmonotonous distance dependence, first increasing, but beyond a critical distance reducing, toward zero. The short-range trend coincides with that predicted for graphene-like trilayers by the random phase approximation, while the long-range trend poses a contrast to the increasing screening with distance by graphene predicted by the many-body dispersion approach. The positive correlation between the screening ratio and the dielectric constant revealed for atomistic layers is reproduced for the bulky dielectric layers.
Collapse
Affiliation(s)
- Jiabao Yang
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Xiaofei Liu
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| | - Wanlin Guo
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
| |
Collapse
|
14
|
Zheng Y, Hoffman A, Huang K. Atomistic Insight into Nitrogen-Terminated Diamond(001) Surfaces by the Adsorption of N, NH, and NH 2: A Density Functional Theory Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:6248-6256. [PMID: 33974432 DOI: 10.1021/acs.langmuir.1c00577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Layer-by-layer construction of diamond devices for spin-sensing calls for the atomistic understanding of the nitrogen species on diamond surfaces. Motivated by recent experiments, we used density functional theory simulations to examine the adsorption of nitrogen species (N, NH, and NH2) on bare and hydrogenated diamond(001) surfaces. On the bare substrate, we find that nitrogen species favor to attack the C═C dimers at low coverages, forming N(ad) and NH(ad) in a bridge configuration and NH2(ad) in a terminal configuration. At increasing coverages up to one full monolayer, the computed adsorption geometries and energetics suggest that the adsorbate-adsorbate interactions are attractive for N(ad), but repulsive for NH(ad) and NH2(ad). On the hydrogenated substrate, the adsorbed nitrogen species are subject to structural modification, as resulted from the weakened adsorbate-substrate interactions. Further, we calculated the vibration of nitrogen species and the 1s core-level shift of surface carbons, providing atomistic insights into the nature of surface bonding. Lastly, we simulated images of representative nitrogen species adsorbed on diamond(001), guiding future work using scanning tunneling microscopy.
Collapse
Affiliation(s)
- Yusen Zheng
- Chemistry Program, Guangdong Technion Israel Institute of Technology, 241 Daxue Road, Shantou, Guangdong Province 515603, China
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Alon Hoffman
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Kai Huang
- Chemistry Program, Guangdong Technion Israel Institute of Technology, 241 Daxue Road, Shantou, Guangdong Province 515603, China
| |
Collapse
|
15
|
The Anh L, Catalan FCI, Kim Y, Einaga Y, Tateyama Y. Boron position-dependent surface reconstruction and electronic states of boron-doped diamond(111) surfaces: an ab initio study. Phys Chem Chem Phys 2021; 23:15628-15634. [PMID: 34264252 DOI: 10.1039/d1cp00689d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Boron-doped diamond (BDD) has attracted much attention in semi-/superconductor physics and electrochemistry, where the surface structures and electronic states play crucial roles. Herein, we systematically examine the structural and electronic properties of the unterminated and H-terminated diamond(111) surfaces by using density functional theory calculations, and the effect of the boron position on them. The surface energy increases compared to that of the undoped case when the boron is located at a deeper position in the diamond bulk, which indicates that boron near the surface can facilitate the surface stability of the BDD in addition to the H-termination. Moreover, the surface energy and projected density of state analyses suggest that the boron can enhance the graphitization of the pristine (ideal) unterminated (111) surface thanks to the alternative sp2-sp3 arrangement on that surface. Finally, we found that surface electronic states depend on the boron's position, i.e., the Fermi energy (EF) is located around the mid-gap position when the boron lies near the surface, instead of showing a p-type semiconductor behavior where the EF lies closer to the valence band maximum.
Collapse
Affiliation(s)
- Le The Anh
- Center for Green Research on Energy and Environmental Materials (GREEN) and International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
| | | | - Yousoo Kim
- Surface and Interface Science Laboratory, RIKEN, 2-1 Horosawa, Wako, Saitama 351-0198, Japan
| | - Yasuaki Einaga
- Department of Chemistry, Keio University, 3-14-1 Hiyoshi, Yokohama 223-8522, Japan
| | - Yoshitaka Tateyama
- Center for Green Research on Energy and Environmental Materials (GREEN) and International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
| |
Collapse
|
16
|
Chen P, Lei B, Dong X, Wang H, Sheng J, Cui W, Li J, Sun Y, Wang Z, Dong F. Rare-Earth Single-Atom La-N Charge-Transfer Bridge on Carbon Nitride for Highly Efficient and Selective Photocatalytic CO 2 Reduction. ACS NANO 2020; 14:15841-15852. [PMID: 33142059 DOI: 10.1021/acsnano.0c07083] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Photocatalytic CO2 conversion into valuable solar fuels is highly appealing, but lack of directional charge-transfer channel and insufficient active sites resulted in limited CO2 reduction efficiency and selectivity for most photocatalytic systems. Herein, we designed and fabricated rare-earth La single-atoms on carbon nitride with La-N charge-transfer bridge as the active center for photocatalytic CO2 reaction. The formation of La single-atoms was certified by spherical aberration-corrected HAADF-STEM, STEM-EELS, EXAFS, and theoretical calculations. The electronic structure of the La-N bridge enables a high CO-yielding rate of 92 μmol·g-1·h-1 and CO selectivity of 80.3%, which is superior to most g-C3N4-based photocatalytic CO2 reductions. The CO production rate remained nearly constant under light irradiation for five cycles of 20 h, indicating its stability. The closely combined experimental and DFT calculations clearly elucidated that the variety of electronic states induced by 4f and 5d orbitals of the La single atom and the p-d orbital hybridization of La-N atoms enabled the formation of charge-transfer channel. The La-N charge bridges are found to function as the key active center for CO2 activation, rapid COOH* formation, and CO desorption. The present work would provide a mechanistic understanding into the utilization of rare-earth single-atoms in photocatalysis for solar energy conversion.
Collapse
Affiliation(s)
- Peng Chen
- Research Center for Environmental and Energy Catalysis, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, China
- The Center of New Energy Materials and Technology, School of New Energy and Materials, Southwest Petroleum University, Chengdu 610500, China
| | - Ben Lei
- Research Center for Environmental and Energy Catalysis, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Xing'an Dong
- Research Center for Environmental and Energy Catalysis, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Hong Wang
- Research Center for Environmental and Energy Catalysis, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Jianping Sheng
- Research Center for Environmental and Energy Catalysis, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Wen Cui
- Research Center for Environmental and Energy Catalysis, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, China
- The Center of New Energy Materials and Technology, School of New Energy and Materials, Southwest Petroleum University, Chengdu 610500, China
| | - Jieyuan Li
- Research Center for Environmental and Energy Catalysis, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yanjuan Sun
- School of Resources and Environment, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Zhiming Wang
- Research Center for Environmental and Energy Catalysis, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Fan Dong
- Research Center for Environmental and Energy Catalysis, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, China
| |
Collapse
|
17
|
Morales-García Á, Rhatigan S, Nolan M, Illas F. On the use of DFT+U to describe the electronic structure of TiO 2 nanoparticles: (TiO 2) 35 as a case study. J Chem Phys 2020; 152:244107. [PMID: 32610938 DOI: 10.1063/5.0012271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
One of the main drawbacks in the density functional theory (DFT) formalism is the underestimation of the energy gaps in semiconducting materials. The combination of DFT with an explicit treatment of the electronic correlation with a Hubbard-like model, known as the DFT+U method, has been extensively applied to open up the energy gap in materials. Here, we introduce a systematic study where the selection of the U parameter is analyzed considering two different basis sets: plane-waves and numerical atomic orbitals (NAOs), together with different implementations for including U, to investigate the structural and electronic properties of a well-defined bipyramidal (TiO2)35 nanoparticle. This study reveals, as expected, that a certain U value can reproduce the experimental value for the energy gap. However, there is a high dependence on the choice of basis set and on the U parameter employed. The present study shows that the linear combination of the NAO basis functions, as implemented in Fritz Haber Institute ab initio molecular simulation (FHI-aims), requires, requires a lower U value than the simplified rotationally invariant approach, as implemented in the Vienna ab initio simulation package (VASP). Therefore, the transfer of U values between codes is unfeasible and not recommended, demanding initial benchmark studies for the property of interest as a reference to determine the appropriate value of U.
Collapse
Affiliation(s)
- Ángel Morales-García
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Stephen Rhatigan
- Tyndall National Institute, University College Cork, Lee Maltings, Cork T12 R5CP, Ireland
| | - Michael Nolan
- Tyndall National Institute, University College Cork, Lee Maltings, Cork T12 R5CP, Ireland
| | - Francesc Illas
- Departament de Ciència de Materials i Química Física & Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, c/Martí i Franquès 1-11, 08028 Barcelona, Spain
| |
Collapse
|
18
|
Sun Z, Gao N, Li H. Structural and electronic properties of c-BN (111) surface with hydrogen/fluorine functionalization and nitrogen-based small-molecule adsorption. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:265002. [PMID: 32135528 DOI: 10.1088/1361-648x/ab7cfa] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Using first-principles density functional theory calculations, we systematically investigate the structural and electrical properties of pure, hydrogen (H) and fluorine (F) functionalized polar (111) cubic boron nitride (c-BN) surface. In the absence of surface functionalization, the reconstructed B-terminated surface is energetically preferable. The hydrogenation is favorable for stabilizing N- and B-terminated surfaces, while the fluorination leads to the stable unreconstructed B-terminated structure due to strong site preference of F atoms. The reconstructed c-BN surface has magnetic characteristic, and the spin density distributions are mainly localized around the interlayer weak B-B bonds. The unreconstructed structures are nonmagnetic. Meantime, the adsorption behavior of nitric oxide (NO) and ammonia (NH3) molecules are investigated on the reconstructed c-BN surface. It is found that the adsorption of NO has a considerable effect on the energy levels near the Fermi level, while the energy levels of NH3 are located at the deep energy level below the Fermi level. Our theoretical results are helpful for understanding experimental phenomenon in practical applications and designing novel c-BN based molecule sensors.
Collapse
Affiliation(s)
- Zhaolong Sun
- State Key Lab of Superhard Materials, College of Physics, Jilin University, Changchun 130012, People's Republic of China
| | | | | |
Collapse
|
19
|
Hou J, Ke C, Chen J, Sun B, Xia Y, Li X, Chen T, Wu Y, Wu Z, Kang J. Reduced Turn-On Voltage and Boosted Mobility in Monolayer WS 2 Transistors by Mild Ar + Plasma Treatment. ACS APPLIED MATERIALS & INTERFACES 2020; 12:19635-19642. [PMID: 32255332 DOI: 10.1021/acsami.0c00001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Monolayer two-dimensional transition-metal dichalcogenides, such as tungsten disulfide (WS2), are regarded as promising candidates for optoelectronic and electronic applications. Although theoretical calculations have predicted outstanding electronic properties of WS2, the performance of WS2-based electronic devices is still limited by the relatively high Schottky barrier and low carrier mobility. In this work, low-energy argon (Ar+) plasma treatment was used as a nondestructive preconditioning technique to tailor the electrical properties of the WS2 monolayer grown by chemical vapor deposition. Photoluminescence and Raman spectroscopy were used to monitor the modified optical properties of WS2 with increasing plasma treatment time. An improved electrical conductivity was observed after a short-time plasma treatment. The physical mechanism was further revealed by a comparative study between top-electrode and bottom-electrode devices and simulation based on the density functional theory. It is concluded that mild Ar+ plasma treatment can effectively lower the Schottky barrier height and the effective mass of carriers, which reduces the turn-on voltage and enhances the mobility, respectively. However, if the processing time is too long, the WS2 lattice structure will be destroyed. This work has provided an effective method for manipulating the Schottky barrier and mobility of monolayer WS2 transistors and paves the way for developing high-performance electronic devices based on 2D semiconductors.
Collapse
Affiliation(s)
- Junfeng Hou
- Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Jiujiang Research Institute, Xiamen University, Xiamen 361005, P. R. China
| | - Congming Ke
- Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Jiujiang Research Institute, Xiamen University, Xiamen 361005, P. R. China
| | - Jiajun Chen
- Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Jiujiang Research Institute, Xiamen University, Xiamen 361005, P. R. China
| | - Baofan Sun
- Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Jiujiang Research Institute, Xiamen University, Xiamen 361005, P. R. China
| | - Yuanzheng Xia
- Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Jiujiang Research Institute, Xiamen University, Xiamen 361005, P. R. China
| | - Xu Li
- Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Jiujiang Research Institute, Xiamen University, Xiamen 361005, P. R. China
| | - Ting Chen
- Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Jiujiang Research Institute, Xiamen University, Xiamen 361005, P. R. China
| | - Yaping Wu
- Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Jiujiang Research Institute, Xiamen University, Xiamen 361005, P. R. China
| | - Zhiming Wu
- Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Jiujiang Research Institute, Xiamen University, Xiamen 361005, P. R. China
| | - Junyong Kang
- Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Jiujiang Research Institute, Xiamen University, Xiamen 361005, P. R. China
| |
Collapse
|
20
|
Jin X, Liu F, Si L, Dou Z, Yan H, Li H, Qu M. A first‐principles investigation on interactions between various surface‐terminated diamond films. SURF INTERFACE ANAL 2019. [DOI: 10.1002/sia.6690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Xiuting Jin
- School of Mechanical and Materials EngineeringNorth China University of Technology Beijing China
| | - Fengbin Liu
- School of Mechanical and Materials EngineeringNorth China University of Technology Beijing China
| | - Lina Si
- School of Mechanical and Materials EngineeringNorth China University of Technology Beijing China
| | - Zhaoliang Dou
- School of Mechanical and Materials EngineeringNorth China University of Technology Beijing China
| | - Hongjuan Yan
- School of Mechanical and Materials EngineeringNorth China University of Technology Beijing China
| | - Hong Li
- School of Mechanical and Materials EngineeringNorth China University of Technology Beijing China
| | - Min Qu
- School of Mechanical and Materials EngineeringNorth China University of Technology Beijing China
| |
Collapse
|
21
|
Rhatigan S, Nolan M. Activation of Water on MnO x-Nanocluster-Modified Rutile (110) and Anatase (101) TiO 2 and the Role of Cation Reduction. Front Chem 2019; 7:67. [PMID: 30809521 PMCID: PMC6379279 DOI: 10.3389/fchem.2019.00067] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 01/24/2019] [Indexed: 11/23/2022] Open
Abstract
Surface modification of titania surfaces with dispersed metal oxide nanoclusters has the potential to enhance photocatalytic activity. These modifications can induce visible light absorption and suppress charge carrier recombination which are vital in improving the efficiency. We have studied heterostructures of Mn4O6 nanoclusters modifying the TiO2 rutile (110) and anatase (101) surfaces using density functional theory (DFT) corrected for on-site Coulomb interactions (DFT + U). Such studies typically focus on the pristine surface, free of the point defects and surface hydroxyls present in real surfaces. In our study we have considered partial hydroxylation of the rutile and anatase surfaces and the role of cation reduction, via oxygen vacancy formation, and how this impacts on a variety of properties governing the photocatalytic performance such as nanocluster adsorption, light absorption, charge separation, and reducibility. Our results indicate that the modifiers adsorb strongly at the surface and that modification extends light absorption into the visible range. MnOx-modified titania can show an off-stoichiometric ground state, through oxygen vacancy formation and cation reduction spontaneously, and both modified rutile and anatase are highly reducible with moderate energy costs. Manganese ions are therefore present in a mixture of oxidation states. Photoexcited electrons and holes localize at cluster metal and oxygen sites, respectively. The interaction of water at the modified surfaces depends on the stoichiometry and spontaneous dissociation to surface bound hydroxyls is favored in the presence of oxygen vacancies and reduced metal cations. Comparisons with bare TiO2 and other TiO2-based photocatalyst materials are presented throughout.
Collapse
Affiliation(s)
| | - Michael Nolan
- Tyndall National Institute, University College Cork, Cork, Ireland
| |
Collapse
|
22
|
Sheng Z, Ma D, He Q, Wu K, Yang L. Mechanism of photocatalytic toluene oxidation with ZnWO 4: a combined experimental and theoretical investigation. Catal Sci Technol 2019. [DOI: 10.1039/c9cy01388a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
ZnWO4 was found to adsorb O2 and H2O, and activate them to produce active radicals. The reactions to form benzyl alcohol and benzoic acid could be carried out spontaneously. The ring opening reaction is more likely to be carried out on benzoic acid.
Collapse
Affiliation(s)
- Zhongyi Sheng
- School of Environment
- Nanjing Normal University
- Nanjing 210023
- China
- Suzhou Industrial Technology Research Institute of Zhejiang University
| | - Dingren Ma
- School of Environment
- Nanjing Normal University
- Nanjing 210023
- China
| | - Qing He
- School of Environment
- Nanjing Normal University
- Nanjing 210023
- China
| | - Kai Wu
- School of Environment
- Nanjing Normal University
- Nanjing 210023
- China
| | - Liu Yang
- School of Environment
- Nanjing Normal University
- Nanjing 210023
- China
| |
Collapse
|
23
|
Liu F, Chen W, Cui Y, Jiao Z, Qu M, Cao L. Interactions between hydrogenated diamond surface and adsorbates with different concentration of NO 2
molecules: A first-principles study. SURF INTERFACE ANAL 2018. [DOI: 10.1002/sia.6514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Fengbin Liu
- College of Mechanical and Materials Engineering; North China University of Technology; Beijing China
| | - Wenbin Chen
- College of Mechanical and Materials Engineering; North China University of Technology; Beijing China
| | - Yan Cui
- College of Mechanical and Materials Engineering; North China University of Technology; Beijing China
| | - Zhiwei Jiao
- College of Mechanical and Materials Engineering; North China University of Technology; Beijing China
| | - Min Qu
- College of Mechanical and Materials Engineering; North China University of Technology; Beijing China
| | - Leigang Cao
- College of Mechanical and Materials Engineering; North China University of Technology; Beijing China
| |
Collapse
|
24
|
James MC, Croot A, May PW, Allan NL. Negative electron affinity from aluminium on the diamond (1 0 0) surface: a theoretical study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:235002. [PMID: 29697065 DOI: 10.1088/1361-648x/aac041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Density functional theory calculations were performed to model the adsorption of up to 1 monolayer (ML) of aluminium on the bare and O-terminated (1 0 0) diamond surface. Large adsorption energies of up to -6.36 eV per atom are observed for the Al-adsorbed O-terminated diamond surface. Most adsorption sites give a negative electron affinity (NEA), with the largest NEAs -1.47 eV on the bare surface (1 ML coverage) and -1.36 eV on the O-terminated surface (0.25 ML coverage). The associated adsorption energies per Al atom for these sites are -4.11 eV and -5.24 eV, respectively. Thus, with suitably controlled coverage, Al on diamond shows promise as a thermally-stable surface for electron emission applications.
Collapse
Affiliation(s)
- Michael C James
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom. Bristol Centre for Functional Nanomaterials, HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, United Kingdom
| | | | | | | |
Collapse
|
25
|
Stehlik S, Ondic L, Varga M, Fait J, Artemenko A, Glatzel T, Kromka A, Rezek B. Silicon-Vacancy Centers in Ultra-Thin Nanocrystalline Diamond Films. MICROMACHINES 2018; 9:E281. [PMID: 30424214 PMCID: PMC6187497 DOI: 10.3390/mi9060281] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/25/2018] [Accepted: 05/30/2018] [Indexed: 11/18/2022]
Abstract
Color centers in diamond have shown excellent potential for applications in quantum information processing, photonics, and biology. Here we report the optoelectronic investigation of shallow silicon vacancy (SiV) color centers in ultra-thin (7⁻40 nm) nanocrystalline diamond (NCD) films with variable surface chemistry. We show that hydrogenated ultra-thin NCD films exhibit no or lowered SiV photoluminescence (PL) and relatively high negative surface photovoltage (SPV) which is ascribed to non-radiative electron transitions from SiV to surface-related traps. Higher SiV PL and low positive SPV of oxidized ultra-thin NCD films indicate an efficient excitation-emission PL process without significant electron escape, yet with some hole trapping in diamond surface states. Decreasing SPV magnitude and increasing SiV PL intensity with thickness, in both cases, is attributed to resonant energy transfer between shallow and bulk SiV. We also demonstrate that thermal treatments (annealing in air or in hydrogen gas), commonly applied to modify the surface chemistry of nanodiamonds, are also applicable to ultra-thin NCD films in terms of tuning their SiV PL and surface chemistry.
Collapse
Affiliation(s)
- Stepan Stehlik
- Institute of Physics ASCR, Cukrovarnická 10, Prague 16200, Czech Republic.
| | - Lukas Ondic
- Institute of Physics ASCR, Cukrovarnická 10, Prague 16200, Czech Republic.
| | - Marian Varga
- Institute of Physics ASCR, Cukrovarnická 10, Prague 16200, Czech Republic.
| | - Jan Fait
- Institute of Physics ASCR, Cukrovarnická 10, Prague 16200, Czech Republic.
- Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, Prague 16627, Czech Republic.
| | - Anna Artemenko
- Institute of Physics ASCR, Cukrovarnická 10, Prague 16200, Czech Republic.
| | - Thilo Glatzel
- Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
| | - Alexander Kromka
- Institute of Physics ASCR, Cukrovarnická 10, Prague 16200, Czech Republic.
| | - Bohuslav Rezek
- Institute of Physics ASCR, Cukrovarnická 10, Prague 16200, Czech Republic.
- Faculty of Electrical Engineering, Czech Technical University in Prague, Technická 2, Prague 16627, Czech Republic.
| |
Collapse
|
26
|
Rhatigan S, Nolan M. Impact of surface hydroxylation in MgO-/SnO-nanocluster modified TiO2 anatase (101) composites on visible light absorption, charge separation and reducibility. CHINESE CHEM LETT 2018. [DOI: 10.1016/j.cclet.2017.11.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
27
|
O'Donnell KM, Edmonds MT, Ristein J, Rietwyk KJ, Tadich A, Thomsen L, Pakes CI, Ley L. Direct observation of phonon emission from hot electrons: spectral features in diamond secondary electron emission. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:395008. [PMID: 25192212 DOI: 10.1088/0953-8984/26/39/395008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this work we use high-resolution synchrotron-based photoelectron spectroscopy to investigate the low kinetic energy electron emission from two negative electron affinity surfaces of diamond, namely hydrogenated and lithiated diamond. For hydrogen-terminated diamond electron emission below the conduction band minimum (CBM) is clearly observed as a result of phonon emission subsequent to carrier thermalization at the CBM. In the case of lithiated diamond, we find the normal conduction band minimum emission peak is asymmetrically broadened to higher kinetic energies and argue the broadening is a result of ballistic emission from carriers thermalized to the CBM in the bulk well before the onset of band-bending. In both cases the spectra display intensity modulations that are the signature of optical phonon emission as the main mechanism for carrier relaxation. To our knowledge, these measurements represent the first direct observation of hot carrier energy loss via photoemission.
Collapse
Affiliation(s)
- Kane M O'Donnell
- Department of Imaging and Applied Physics, Curtin University, Bentley WA 6102 Australia
| | | | | | | | | | | | | | | |
Collapse
|
28
|
De La Pierre M, Bruno M, Manfredotti C, Nestola F, Prencipe M, Manfredotti C. The (100), (111) and (110) surfaces of diamond: anab initioB3LYP study. Mol Phys 2013. [DOI: 10.1080/00268976.2013.829250] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
29
|
Yao X, Feng Y, Hu Z, Zhang L, Wang EG. Dimerization of boron dopant in diamond (100) epitaxy induced by strong pair correlation on the surface. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:045011. [PMID: 23264460 DOI: 10.1088/0953-8984/25/4/045011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Experiments have shown that boron incorporation in diamond epitaxies is orientation dependent. Our first-principles calculations reveal that at a (100) surface, the formation of the boron dimer is more favored than that of the monomer, indicating a high density of ineffective boron formed under heavy doping. The reconstructed surface layer of carbon dimers in which the electrons are strongly pair correlated provides the mechanism. Hydrogen adsorption affects the correlation and thus the favorability of boron dimer formation, while at a (111) surface, the formation of boron monomer is more favored due to the less correlated surface electrons and hydrogen adsorption has no effect on the favorability.
Collapse
Affiliation(s)
- Xiaolong Yao
- School of Physics, Nankai University, Tianjin 300071, People's Republic of China
| | | | | | | | | |
Collapse
|
30
|
Tarala VA, Sinel’nikov BM. Model of the nucleation and growth of amorphous and crystalline films of diamond-like materials: The (100) plane. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2012. [DOI: 10.1134/s0036024412040243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
31
|
Yang J, Tse JS, Iitaka T. First-principles study of liquid gallium at ambient and high pressure. J Chem Phys 2011; 135:044507. [DOI: 10.1063/1.3615936] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
32
|
Ma Y, Dai Y, Wei W, Liu X, Huang B. Ag adsorption on Cd-terminated CdS (0001) and S-terminated CdS (0001̄) surfaces: First-principles investigations. J SOLID STATE CHEM 2011. [DOI: 10.1016/j.jssc.2011.01.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
33
|
Abstract
ABSTRACTPresented here are results of ab initio Density Functional Theory (DFT) structural relaxations performed on dehydrogenated and monohydrogenated nanocrystalline diamond structures of octahedral {111} and cuboctahedral morphologies, up to approximately 2nm in diameter. Our results in this size range show a transition of dehydrogenated nanodiamond clusters into carbon onion-like structures, with preferential exfoliation of the C(111) surfaces, in agreement with experimental observations. However, we have found that this transition may be prevented by hydrogenation of the surfaces. Bonding between atoms in the surface layers of the relaxed structures, and interlayer bonding has been investigated using Wannier functions.
Collapse
|
34
|
Park K, Heremans JJ, Scarola VW, Minic D. Robustness of topologically protected surface states in layering of Bi2Te3 thin films. PHYSICAL REVIEW LETTERS 2010; 105:186801. [PMID: 21231125 DOI: 10.1103/physrevlett.105.186801] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Indexed: 05/30/2023]
Abstract
Bulk Bi2Te3 is known to be a topological insulator. We investigate surface states of Bi2Te3(111) thin films of one to six quintuple layers using density-functional theory including spin-orbit coupling. We construct a method to identify topologically protected surface states of thin film topological insulators. Applying this method to Bi2Te3 thin films, we find that the topological nature of the surface states remains robust with the film thickness and that the films of three or more quintuple layers have topologically nontrivial surface states, which agrees with experiments.
Collapse
Affiliation(s)
- Kyungwha Park
- Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA
| | | | | | | |
Collapse
|
35
|
Images and Energy Distributions of Electrons Emitted from a Diamond pn-Junction Diode. E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 2009. [DOI: 10.1380/ejssnt.2009.660] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
36
|
Janetzko F, Bredow T, Geudtner G, Köster AM. Boron-doped diamond: Investigation of the stability of surface-doping versus bulk-doping using cyclic cluster model calculations. J Comput Chem 2008; 29:2295-301. [PMID: 18478585 DOI: 10.1002/jcc.20997] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Boron-doped bulk diamond and the boron-doped hydrogen terminated (001) surface of diamond were investigated using the cyclic cluster model. Structure and stability of the hydrogen-terminated (001) surface were calculated and compared with experimental and other theoretical results from the literature. Boron-doping was modeled by substitution of a carbon atom by a boron atom in different positions with increasing distance from the surface up to boron-doped bulk diamond. In agreement with experiments on nanoclusters, boron is most stable in the first surface layers. (c) 2008 Wiley Periodicals, Inc. J Comput Chem, 2008.
Collapse
Affiliation(s)
- Florian Janetzko
- Institut für Physikalische und Theoretische Chemie, Universität Bonn, Germany
| | | | | | | |
Collapse
|
37
|
Jin H, Dai Y, Long R, Guo M, Huang B, Zhang R. First principles studies for formation mechanism and properties of ethylene molecule adsorbing on diamond (100) surface. J Chem Phys 2008; 128:114710. [DOI: 10.1063/1.2894867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
38
|
Qi D, Liu L, Gao X, Ouyang T, Chen S, Loh KP, Wee ATS. Tuning the electron affinity and secondary electron emission of diamond (100) surfaces by Diels-Alder reaction. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:9722-7. [PMID: 17705410 DOI: 10.1021/la701285h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The tuning of electron affinity and secondary electron emission on diamond (100) surfaces due to cycloaddition with 1,3-butadiene is investigated by photoemission experiments and density functional theory (DFT) calculations. A significant reduction in electron affinity up to 0.7 eV and enhancement of secondary electron emission were observed after 1,3-butadiene adsorption. The lowering of vacuum level via 1,3-butadiene adsorption is supported by DFT calculations. The C-H bonds in the covalently bonded organics on diamond contribute to the enhanced secondary electron emission and reduced electron affinity in a mechanism similar to that of C-H bonds on hydrogenated diamond surfaces. This combination of strong secondary emission and low electron affinity by the organic functionalization of diamond has potential applications in diamond-based molecular electronic devices.
Collapse
Affiliation(s)
- Dongchen Qi
- Department of Physics, National University of Singapore, 2 Science Drive 3 Singapore 117542
| | | | | | | | | | | | | |
Collapse
|
39
|
Schwartz MP, Barlow DE, Russell JN, Weidkamp KP, Butler JE, D'Evelyn MP, Hamers RJ. Semiconductor surface-induced 1,3-hydrogen shift: the role of covalent vs zwitterionic character. J Am Chem Soc 2007; 128:11054-61. [PMID: 16925421 DOI: 10.1021/ja060598w] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) are used to compare the reaction of 1,2-cyclohexanedione (1,2-CHD) with Si(001) and diamond(001) surface dimers under ultra-high-vacuum conditions. 1,2-CHD is known to undergo a keto-enol tautomerization, with the monoenol being the primary equilibrium species in the solid and gas phases. XPS and FTIR data demonstrate that 1,2-CHD reacts with diamond(001) through the OH group of the monoenol, resulting in only one O atom being bonded to the surface. In contrast, XPS and FTIR data suggest that both oxygen atoms in the 1,2-CHD molecule bond via Si-O-C linkages to the Si(001) surface dimer, and that the molecule undergoes an intramolecular 1,3-H shift. While the Si(001) and diamond(001) surfaces are both comprised of surface dimers, the diamond(001) dimer is symmetric, with little charge separation, whereas the Si(001) dimer is tilted and exhibits zwitterionic character. The different reaction products that are observed when clean Si(001) and diamond(001) surfaces are exposed to 1,2-CHD demonstrate the importance of charge separation in promoting a 1,3-H shift and provide new mechanistic insights that may be applicable to a variety of organic reactions.
Collapse
Affiliation(s)
- Michael P Schwartz
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, Chemistry Division, U.S. Naval Research Laboratory, Washington, D.C. 20375, USA
| | | | | | | | | | | | | |
Collapse
|
40
|
Zhang L, Ren T, Wang H, Wang M, Yang C, Han K. Density Functional Theory Investigation of Product Distribution following Reaction of Acrylonitrile on Diamond (001)-2×1 Surface. J Phys Chem B 2006; 110:23395-402. [PMID: 17107190 DOI: 10.1021/jp063714q] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The reaction of acrylonitrile with the C(001)-2 x 1 surface has been investigated by employing density functional cluster model calculations. The calculations revealed eight possible reaction pathways for acrylonitrile with the surface dimer. Full geometry optimized structures were obtained for all adducts, including intra- and interdimer reaction products. These results were analyzed in terms of both the total energy values and the detailed optimized geometries. We find that the reaction of acrylonitrile with the diamond (001) surface occurs primarily through its nonpolar C=C group and the intradimer [2+2](cc) product is the dominant product. All these results are in good agreement with the experimental work by Schwartz. It is noteworthy that the isomerization process plays an important role in the chemisorption process. Both intradimer [4+2] product and interdimer [2+2](cc) product can isomerize to the intradimer [2+2](cc) product. The present study shows that the isomerization between intradimer [4+2] product and intradimer [2+2](cc) product is slightly favorable over the direct path to formation of the intradimer [2+2](cc) product.
Collapse
Affiliation(s)
- Laibin Zhang
- School of Physics and Electronic Engineering, Key Laboratory of Atomic and Molecular Physics of Shandong Province, Ludong University, Yantai, 264025, China
| | | | | | | | | | | |
Collapse
|
41
|
Liu F, Wang J, Liu B, Li X, Chen D. Electronic structures of the oxygenated diamond (100) surfaces. CHINESE SCIENCE BULLETIN-CHINESE 2006. [DOI: 10.1007/s11434-006-2139-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
42
|
|
43
|
Ssenyange S, Anariba F, Bocian DF, McCreery RL. Covalent bonding of alkene and alkyne reagents to graphitic carbon surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:11105-12. [PMID: 16285778 DOI: 10.1021/la0516173] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Various aromatic and aliphatic alkynes and one alkene were covalently bonded to sp(2)-hybridized carbon surfaces by heat treatment in an argon atmosphere. X-ray photoelectron spectroscopy, Raman, and FTIR spectra of the modified surfaces showed that the molecules were intact after the 400 degrees C heat treatment but that the alkyne group had reacted with the surface to form a covalent bond. Alkynes with ferrocene and porphyrin centers exhibited chemically reversible voltammetric waves that could be cycled many times. Atomic force microscopy of the modified surfaces indicated a thickness of the molecular layer consistent with monolayer coverage, and surface coverage determined by voltammetry was also in the monolayer range. Raman spectroscopy of the porphyrin monolayers formed from a porphyrin alkyne showed no evidence for dimer formation, although multilayer formation may occur at undetected levels. FTIR spectra of the porphyrin-modified carbon surfaces were well-defined, similar to the parent molecule, and indicative of an average tilt angle between the porphyrin plane and the surface normal of 37 degrees . The bond between the molecular monolayer and the carbon surface was quite stable, withstanding sonication in tetrahydrofuran, mild aqueous acid and base, and repeated voltammetric cycling in propylene carbonate electrolyte. Heat treatment of alkynes and alkenes appears to be a generally useful method for modifying carbon surfaces, which can be applied to both aromatic and aliphatic molecules.
Collapse
Affiliation(s)
- Solomon Ssenyange
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, USA
| | | | | | | |
Collapse
|
44
|
Sque SJ, Jones R, Briddon PR. Hydrogenation and oxygenation of the (100) diamond surface and the consequences for transfer doping. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/pssa.200561911] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
45
|
Barnard AS, Russo SP, Snook IK. First-Principles Modeling of Dopants in C29 and C29H24 Nanodiamonds. J Phys Chem B 2005; 109:11991-5. [PMID: 16852479 DOI: 10.1021/jp051519q] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Presented here is our continuing first-principles density functional theory study of the structural stability of a select group of dopants in diamond nanocrystals. On the basis of the work of others concerning dopants in diamond and endohedral atoms in fullerenes, the dopants selected for use here are oxygen, aluminum, silicon, phosphorus, and sulfur. These atoms were included substitutionally in the center of a 29-carbon-atom nanodiamond crystal, and each structure was relaxed using the Vienna Ab Initio Simulation Package. We describe the bonding and structure of the relaxed doped nanocrystals via examination of the electron charge density and point group symmetry. In combination with our previously reported results, it is anticipated that these results will assist in providing a better understanding of the mechanical stability of doped nanodiamonds for use in diamond nanodevices.
Collapse
Affiliation(s)
- A S Barnard
- Center for Nanoscale Materials, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA
| | | | | |
Collapse
|
46
|
Schwartz MP, Barlow DE, Russell JN, Butler JE, D'Evelyn MP, Hamers RJ. Adsorption of Acrylonitrile on Diamond and Silicon (001)−(2 × 1) Surfaces: Effects of Dimer Structure on Reaction Pathways and Product Distributions. J Am Chem Soc 2005; 127:8348-54. [PMID: 15941268 DOI: 10.1021/ja042701s] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) are used to compare the reaction of acrylonitrile with Si(001) and C(001) (diamond) surfaces. Our results show that reaction with Si(001) and C(001) yield very different product distributions that result from fundamental differences in the ionic character of these surfaces. While acrylonitrile reacts with the C(001) surface via a [2 + 2] cycloaddition reaction in a manner similar to nonpolar molecules such as alkenes and disilenes, reaction with the Si(001) surface occurs largely through the nitrile group. This work represents the first experimental example of how differences in dimer structure lead to very different chemistry for C(001) compared to that for Si(001). The fact that Si(001) reacts with the strongly polar nitrile group of acrylonitrile indicates that the zwitterionic character of this surface controls its reactivity. C(001) dimers, on the other hand, behave more like a true molecular double bond, albeit a highly strained one. Consequently, while alternative strategies will be necessary for chemical modification of Si(001), traditional schemes from organic chemistry for functionalization of alkenes and disilenes may be available for building molecular layers on C(001).
Collapse
Affiliation(s)
- Michael P Schwartz
- Department of Chemistry, 1100 University Avenue, University of Wisconsin, Madison WI 53706, USA
| | | | | | | | | | | |
Collapse
|
47
|
Palummo M, Pulci O, Del Sole R, Marini A, Schwitters M, Haines SR, Williams KH, Martin DS, Weightman P, Butler JE. Reflectance anisotropy spectra of the diamond (100)-(2x1) surface: evidence of strongly bound surface state excitons. PHYSICAL REVIEW LETTERS 2005; 94:087404. [PMID: 15783931 DOI: 10.1103/physrevlett.94.087404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2004] [Indexed: 05/24/2023]
Abstract
We compare the results of ab initio calculations with measured reflection anisotropy spectra and show that strongly bound surface-state excitons occur on the clean diamond (100) surface. These excitons are found to have a binding energy close to 1 eV, the strongest ever observed at a semiconductor surface. Important electron-hole interaction effects on the line shape of the optical transitions above the surface-state gap are also found.
Collapse
Affiliation(s)
- Maurizia Palummo
- Dipartimento di Fisica-Universitá di Roma, Tor Vergata and Istituto Nazionale per la Fisica della Materia, I-00133 Rome, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Jia Y, Zhu W, Wang EG, Huo Y, Zhang Z. Initial stages of Ti growth on diamond (100) surfaces: from single adatom diffusion to quantum wire formation. PHYSICAL REVIEW LETTERS 2005; 94:086101. [PMID: 15783905 DOI: 10.1103/physrevlett.94.086101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2004] [Indexed: 05/24/2023]
Abstract
Using first-principles total energy calculations within density functional theory, we investigate the energetics, kinetics, and transport properties of Ti on clean and hydrogen-terminated diamond (100)-2x1 surfaces at increasing Ti coverages. On a clean surface, an isolated Ti adatom prefers to adsorb on top of a C-C dimer row, and also diffuses faster along the dimer row direction. As the Ti coverage increases, the preferred adsorption site converts from an atop site to a site located between the dimer rows. Passivation of the surface at the monohydride coverage not only greatly enhances the Ti mobility, but also weakens the diffusion isotropy. Based on these energetic and kinetic characteristics, we propose a viable approach to fabricate ideal Ti quantum wires on hydrogen-terminated diamond substrates.
Collapse
Affiliation(s)
- Yu Jia
- School of Physics and Engineering, Zhengzhou University, Zhengzhou, Henan 450052, China
| | | | | | | | | |
Collapse
|
49
|
Barnard* A, Bath† P, Russo S, Snook¶ I. A Monte Carlo Study of Surface Reconstruction in (100) and (111) Diamond Surfaces and Nanodiamond. MOLECULAR SIMULATION 2004. [DOI: 10.1080/08927020310001640061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
50
|
Tamura H, Gordon MS. Multiconfigurational self-consistent field study of the silicon carbide (001) surface. J Chem Phys 2003. [DOI: 10.1063/1.1617973] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|