1
|
Chen Y, Lyu N, Zhang J, Yan S, Peng C, Yang C, Lv X, Hu C, Kuang M, Zheng G. Tailoring the *CO and *H Coverage for Selective CO 2 Electroreduction to CH 4 or C 2H 4. Small 2024; 20:e2308004. [PMID: 37992242 DOI: 10.1002/smll.202308004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/27/2023] [Indexed: 11/24/2023]
Abstract
In the electrochemical CO2 reduction reaction (CO2RR), the coverages of *CO and *H intermediates on a catalyst surface are critical for the selective generation of C1 or C2 products. In this work, we have synthesized several CuxZnyMnz ternary alloy electrocatalysts, including Cu8ZnMn, Cu8Zn6Mn, and Cu8ZnMn2, by varying the doping compositions of Zn and Mn, which are efficient in binding *CO and *H adsorbates in the CO2 electroreduction process, respectively. The increase of *H coverage allows to promotion of the CH4 and H2 formation, while the increase of the *CO coverage facilitates the production of C2H4 and CO. As a result, the Cu8ZnMn catalyst presented a high CO2-to-CH4 partial current density (-418 ± 22 mA cm-2) with a Faradaic efficiency of 55 ± 2.8%, while the Cu8Zn6Mn catalyst exhibited a CO2-to-C2H4 partial current density (-440 ± 41 mA cm-2) with a Faradaic efficiency of 58 ± 4.5%. The study suggests a useful strategy for rational design and fabrication of Cu electrocatalysts with different doping for tailoring the reduction products.
Collapse
Affiliation(s)
- Yangshen Chen
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China
| | - Naixin Lyu
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China
| | - Junbo Zhang
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China
| | - Shuai Yan
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China
| | - Chen Peng
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China
| | - Chao Yang
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China
| | - Ximeng Lv
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China
| | - Cejun Hu
- School of Materials Science and Engineering, Fuzhou University, Fujian, 350108, China
| | - Min Kuang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai, 201620, China
| | - Gengfeng Zheng
- Laboratory of Advanced Materials, Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200438, China
| |
Collapse
|
2
|
Li R, Yu J, Yao B, Huang X, Fu Z, Zhou Z, Yuan G, Xu J, Gao L. Controllable growth of wafer-scale monolayer transition metal dichalcogenides ternary alloys with tunable band gap. Nanotechnology 2022; 34:075603. [PMID: 36384029 DOI: 10.1088/1361-6528/aca33a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 11/16/2022] [Indexed: 06/16/2023]
Abstract
The tuning of band gap is very important for the application of two-dimensional (2D) materials in optoelectronic devices. Alloying of 2D transition metal dichalcogenides (TMDCs) is an important way to tune the wide band gap. In this study, we report a multi-step vapor deposition method to grow monolayer TMDC ternary alloy films with wafer scale, including Mo1-xWxS2, Mo1-xWxSe2and MoS2xSe2(1-x), which are accurately controllable in the elemental proportion (xis from 0 to 1). The band gap of the three 2D ternary alloy materials are continuously tuned for the whole range of metal and chalcogen compositions. The metal compositions are controlled by the as-deposited thickness. Raman, photoluminescence, elemental maps and TEM show the high spatial homogeneity in the compositions and optical properties across the whole wafer. The band gap can be continuously tuned from 1.86 to 1.99 eV for Mo1-xWxS2, 1.56 to 1.65 eV for Mo1-xWxSe2, 1.56 to 1.86 eV for MoS2xSe2(1-x). Electrical transport measurements indicate that Mo1-xWxS2and MoS2xSe2(1-x)monolayers shown-type semiconductor behaviors, and the carrier types of Mo1-xWxSe2can be tuned asn-type, bipolar andp-type. Moreover, this control process can be easily generalized to other 2D alloy films, even to quaternary or multi-element alloy materials. Our study presents a promising route for the preparation of large-scale homogeneous monolayer TMDC alloys and the application for future functional devices.
Collapse
Affiliation(s)
- Rongsheng Li
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nanotechnology, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Junyao Yu
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nanotechnology, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Bing Yao
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nanotechnology, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Xianlei Huang
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nanotechnology, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Zihao Fu
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nanotechnology, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Zhenjia Zhou
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nanotechnology, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Guowen Yuan
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nanotechnology, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Jie Xu
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nanotechnology, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| | - Libo Gao
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nanotechnology, School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China
| |
Collapse
|
3
|
Padmanathan N, Lal S, Gautam D, Razeeb KM. Amorphous Framework in Electrodeposited CuBiTe Thermoelectric Thin Films with High Room-Temperature Performance. ACS Appl Electron Mater 2021; 3:1794-1803. [PMID: 35156045 PMCID: PMC8824429 DOI: 10.1021/acsaelm.1c00063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/26/2021] [Indexed: 06/14/2023]
Abstract
Bismuth telluride-based alloys are the most efficient thermoelectric materials near room temperature and widely used in commercial thermoelectric devices. Nevertheless, their thermoelectric performance needs to be improved further for wide-scale implementation either as a thermoelectric generator or cooler. Here, we propose a simultaneous codeposition of CuBiTe thin films and their phase transition strategy via the traditional electrodeposition process. With just 13 atom % Cu doping, crystalline-to-amorphous phase transformation resulted for the electroplated CuBiTe alloy. A close look at the alloy composition revealed spike-shaped nanocrystalline Bi2Te3 embedded in the CuBiTe amorphous matrix. Our result shows an exceptionally high power factor (3.02 mW m-1 K-2), which comes from the enhanced Seebeck coefficient (-275 μV K-1) and high electrical conductivity (3.99 × 104 S m-1) of CuBiTe films. Therefore, it can be suggested that the adopted strategy to form a unique nanocrystallite-embedded amorphous framework provides a platform to develop next-generation high-performance thermoelectric materials with an extraordinary power factor.
Collapse
Affiliation(s)
- N. Padmanathan
- Micro-Nano
Systems Centre, Tyndall National Institute,
University College Cork, Dyke Parade, Lee Maltings, Cork T12 R5CP, Ireland
- Department
of Physics, Karpagam Academy of Higher Education, Coimbatore, Tamilnadu 641021, India
| | - Swatchith Lal
- Micro-Nano
Systems Centre, Tyndall National Institute,
University College Cork, Dyke Parade, Lee Maltings, Cork T12 R5CP, Ireland
| | - Devendraprakash Gautam
- Micro-Nano
Systems Centre, Tyndall National Institute,
University College Cork, Dyke Parade, Lee Maltings, Cork T12 R5CP, Ireland
| | - Kafil M. Razeeb
- Micro-Nano
Systems Centre, Tyndall National Institute,
University College Cork, Dyke Parade, Lee Maltings, Cork T12 R5CP, Ireland
| |
Collapse
|
4
|
Kim D, Oh GH, Kim A, Shin C, Park J, Kim SI, Kim T. Atomic Layer MoS 2xTe 2(1-x) Ternary Alloys: Two-Dimensional van der Waals Growth, Band gap Engineering, and Electrical Transport. ACS Appl Mater Interfaces 2020; 12:40518-40524. [PMID: 32808524 DOI: 10.1021/acsami.0c11154] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Ternary alloys in two-dimensional (2D) transition-metal dichalcogenides allow band gap tuning and phase engineering and change the electrical transport type. A process of 2D van der Waals epitaxial growth of molybdenum sulfide telluride alloys (MoS2xTe2(1-x), 0 ≤ x ≤ 1) is presented for synthesizing few-atomic-layer films on SiO2 substrates using metal-organic chemical vapor deposition. Raman spectra, X-ray photoelectron spectra, photoluminescence (PL), and electrical transport properties of few-atomic-layer MoS2xTe2(1-x) (0 ≤ x ≤ 1) films are systematically investigated. The strong PL peaks at 80 K from MoS2xTe2(1-x) (0.45 ≤ x ≤ 0.93) reveal a composition-controllable optical band gap (Eg = 1.55-1.91 eV at 80 K). Electrical transport properties of MoS2xTe2(1-x) alloys, where 0 ≤ x ≤ 0.8 and 0.93 ≤ x ≤ 1, exhibit p-type and n-type semiconducting behaviors, respectively. Remarkably, an increase in the Te composition of a few-atomic-layer MoS2xTe2(1-x) (0 ≤ x ≤ 1) film left-shifts the threshold voltage of a MoS2xTe2(1-x) (0 ≤ x ≤ 1) field-effect transistor. The narrower band gap energies of MoS2xTe2(1-x) films with higher Te content cause a decrease in the on/off current ratios.
Collapse
Affiliation(s)
- DongHwan Kim
- Materials and Convergence Metrology Institute, Korea Research Institute of Standards and Science, Daejeon 34113, South Korea
| | - Guen Hyung Oh
- Department of Electrical Engineering and Smart Grid Research Center, Jeonbuk National University, Jeonju 54896, South Korea
| | - Ansoon Kim
- Materials and Convergence Metrology Institute, Korea Research Institute of Standards and Science, Daejeon 34113, South Korea
| | - ChaeHo Shin
- Materials and Convergence Metrology Institute, Korea Research Institute of Standards and Science, Daejeon 34113, South Korea
| | - Jonghoo Park
- Department of Electrical Engineering, Kyungpook National University, Daegu 41566, South Korea
| | - Sang-Il Kim
- Department of Materials Science and Engineering, University of Seoul, 163 Seoulsiripdae-ro, Dongdaemun-gu, Seoul 02504, South Korea
| | - TaeWan Kim
- Department of Electrical Engineering and Smart Grid Research Center, Jeonbuk National University, Jeonju 54896, South Korea
| |
Collapse
|
5
|
Lu W, Xia X, Wei X, Li M, Zeng M, Guo J, Cheng S. Nanoengineering 2D Dendritic PdAgPt Nanoalloys with Edge-Enriched Active Sites for Enhanced Alcohol Electroxidation and Electrocatalytic Hydrogen Evolution. ACS Appl Mater Interfaces 2020; 12:21569-21578. [PMID: 32309921 DOI: 10.1021/acsami.0c01690] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Lots of research studies reveal that the surface atoms on the top/bottom facets of the nanosheets are the key features in enhancing electrocatalytic activity while the edge and corner sites of electrocatalysts often possess superior activity. Herein, we report 2D dendritic PdAgPt ternary nanoalloys with abundant crystal defects such as steps, twin boundary, and atomic holes, which can effectively work as catalytic active-sites. The morphology of PdAgPt nanoalloys can be regulated readily from dendritic nanosheets to nanowheels. Compared with binary Pd68Ag32 nanodendrites, Pd62Pt38 nanospheres, and Pt/C catalyst, the composition- and morphology-optimized Pd43Ag21Pt36 nanowheels exhibit the best mass/specific activity and stability for methanol/ethanol oxidation reaction (MOR/EOR). The mass peak current density for EOR/MOR of Pd43Ag21Pt36 is 7.08/3.50 times of the Pt/C catalyst. Simultaneously, the hydrogen evolution reaction performance of the Pd43Ag21Pt36 nanowheels in terms of the lowest overpotential of 9 mv at a current density of 10 mA/cm2 and high electrochemical stability is much better than that of binary Pd68Ag32 nanodendrites, Pd62Pt38 nanospheres, and Pt/C.
Collapse
Affiliation(s)
- Wenya Lu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215021, China
| | - Xinyue Xia
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215021, China
| | - Xiaoxu Wei
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215021, China
| | - Manman Li
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215021, China
| | - Min Zeng
- Key Laboratory of Thin Film and Microfabrication (Ministry of Education), Department of Micro/Nano Electronics, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jun Guo
- Testing & Analysis Center, Soochow University, Suzhou 215123, China
| | - Si Cheng
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215021, China
| |
Collapse
|
6
|
Swelm W, Al-Ghamdi A, Jilani A, Iqbal J. Facile Synthesis of Ternary Alloy of CdSe 1-xS x Quantum Dots with Tunable Absorption and Emission of Visible Light. Nanomaterials (Basel) 2018; 8:nano8120979. [PMID: 30486405 PMCID: PMC6315846 DOI: 10.3390/nano8120979] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 11/18/2018] [Accepted: 11/21/2018] [Indexed: 12/03/2022]
Abstract
The synthesis of alloyed semiconductor quantum dots has produced structures that have distinct properties in comparison with both their bulk counterparts and their parent binary semiconductor quantum dots. In this work, the quantum confined structures of a ternary alloy of CdSe1−xSx were synthesized by one-pot synthesis method in an aqueous medium at a low temperature and capped with 3-mercaptopropoionic acid. Structures of the synthesized quantum dots were investigated by energy dispersive X-ray, X-ray diffraction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The obtained quantum dots had modified cubic structures as proven by X-ray diffraction and selected area electron diffraction. The optical properties of the synthesized quantum dots were characterized by optical absorption, photoluminescence, and color analysis. Optical absorption investigation revealed a widening of the band gap of CdSe1−xSx with increasing S content. This widening increased for the samples suspended in water relative to the samples measured in powder form due to the difference in the environment of the two cases. The size determined from the optical absorption measurements was found to be compatible with the sizes obtained from the X-ray diffraction with the value of bowing parameter around 1, which indicated a graded diffusion of sulfur. It was also ascertained that the emission of different compositions covered the most visible range with a small full width at half maximum. The x and y values of the chromaticity coordinates decreased with increasing sulfur content of up to 15%, while the z value increased.
Collapse
Affiliation(s)
- Wageh Swelm
- Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
- Physics and Engineering Mathematics Department, Faculty of Electronic Engineering, Menoufia University, Menouf 32952, Egypt.
| | - Ahmed Al-Ghamdi
- Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
| | - Asim Jilani
- Center of Nanotechnology, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
| | - Javed Iqbal
- Center of Nanotechnology, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
| |
Collapse
|
7
|
Leteba GM, Mitchell DRG, Levecque PBJ, Lang CI. Solution-Grown Dendritic Pt-Based Ternary Nanostructures for Enhanced Oxygen Reduction Reaction Functionality. Nanomaterials (Basel) 2018; 8:nano8070462. [PMID: 29949875 PMCID: PMC6070889 DOI: 10.3390/nano8070462] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/16/2018] [Accepted: 06/22/2018] [Indexed: 11/16/2022]
Abstract
Nanoalloys with anisotropic morphologies of branched and porous internal structures show great promise in many applications as high performance materials. Reported synthetic approaches for branched alloy nanostructures are, however, limited by the synthesis using a seed-growth process. Here, we demonstrate a conveniently fast and one-pot solution-phase thermal reduction strategy yielding nanoalloys of Pt with various solute feed ratios, exhibiting hyperbranched morphologies and good dispersity. When Pt was alloyed with transition metals (Ni, Co, Fe), we observed well-defined dendritic nanostructures in PtNi, PtCo and Pt(NiCo), but not in PtFe, Pt(FeNi) or Pt(FeCo) due to the steric hindrance of the trivalent Fe(acac)₃ precursor used during synthesis. In the case of Pt-based nanoalloys containing Ni and Co, the dendritic morphological evolution observed was insensitive to large variations in solute concentration. The functionality of these nanoalloys towards the oxygen reduction reaction (ORR); however, was observed to be dependent on the composition, increasing with increasing solute content. Pt₃(NiCo)₂ exhibited superior catalytic activity, affording about a five- and 10-fold enhancement in area-specific and mass-specific catalytic activities, respectively, compared to the standard Pt/C nanocatalyst. This solution-based synthetic route offers a new approach for constructing dendritic Pt-based nanostructures with excellent product yield, monodispersity and high crystallinity.
Collapse
Affiliation(s)
- Gerard M Leteba
- Department of Chemical Engineering, Catalysis Institute, University of Cape Town, Cape Town 7700, South Africa.
- School of Engineering, Macquarie University, Sydney NSW 2109, Australia.
| | - David R G Mitchell
- Electron Microscopy Centre, University of Wollongong, Wollongong NSW 2522, Australia.
| | - Pieter B J Levecque
- Department of Chemical Engineering, Catalysis Institute, University of Cape Town, Cape Town 7700, South Africa.
| | - Candace I Lang
- School of Engineering, Macquarie University, Sydney NSW 2109, Australia.
| |
Collapse
|
8
|
Park J, Kanti Kabiraz M, Kwon H, Park S, Baik H, Choi SI, Lee K. Radially Phase Segregated PtCu@PtCuNi Dendrite@Frame Nanocatalyst for the Oxygen Reduction Reaction. ACS Nano 2017; 11:10844-10851. [PMID: 29024581 DOI: 10.1021/acsnano.7b04097] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Pt-based alloy nanoframes have shown great potential as electrocatalysts toward the oxygen reduction reaction (ORR) in fuel cells. However, the intrinsically infirm nanoframes could be severely deformed during extended electro-cyclings, which eventually leads to the loss of the initial catalytic activity. Therefore, the structurally robust nanoframe is a worthy synthetic target. Furthermore, ternary alloy phase electrocatalysts offer more opportunities in optimizing the stability and activity than binary alloy ones. Herein, we report a robust PtCuNi ternary nanoframe, structurally fortified with an inner-lying PtCu dendrite, which shows a highly active and stable catalytic performance toward ORR. Remarkably, the PtCu@PtCuNi catalyst exhibited 11 and 16 times higher mass and specific activities than those of commercial Pt/C.
Collapse
Affiliation(s)
- Jongsik Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) , Seoul 02841, Korea
- Department of Chemistry and Research Institute for Natural Sciences, Korea University , Seoul 02841, Korea
| | - Mrinal Kanti Kabiraz
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University , Daegu 41566, Korea
| | - Hyukbu Kwon
- Department of Chemistry and Research Institute for Natural Sciences, Korea University , Seoul 02841, Korea
| | - Suhyun Park
- Department of Chemistry and Research Institute for Natural Sciences, Korea University , Seoul 02841, Korea
| | - Hionsuck Baik
- Korea Basic Science Institute (KBSI) , Seoul 02841, Korea
| | - Sang-Il Choi
- Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University , Daegu 41566, Korea
| | - Kwangyeol Lee
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) , Seoul 02841, Korea
- Department of Chemistry and Research Institute for Natural Sciences, Korea University , Seoul 02841, Korea
| |
Collapse
|
9
|
Park J, Sa YJ, Baik H, Kwon T, Joo SH, Lee K. Iridium-Based Multimetallic Nanoframe@Nanoframe Structure: An Efficient and Robust Electrocatalyst toward Oxygen Evolution Reaction. ACS Nano 2017; 11:5500-5509. [PMID: 28599106 DOI: 10.1021/acsnano.7b00233] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Nanoframe electrocatalysts have attracted great interest due to their inherently high active surface area per a given mass. Although recent progress has enabled the preparation of single nanoframe structures with a variety of morphologies, more complex nanoframe structures such as a double-layered nanoframe have not yet been realized. Herein, we report a rational synthetic strategy for a structurally robust Ir-based multimetallic double-layered nanoframe (DNF) structure, nanoframe@nanoframe. By leveraging the differing kinetics of dual Ir precursors and dual transition metal (Ni and Cu) precursors, a core-shell-type alloy@alloy structure could be generated in a simple one-step synthesis, which was subsequently transformed into a multimetallic IrNiCu DNF with a rhombic dodecahedral morphology via selective etching. The use of single Ir precursor yielded single nanoframe structures, highlighting the importance of employing dual Ir precursors. In addition, the structure of Ir-based nanocrystals could be further controlled to DNF with octahedral morphology and CuNi@Ir core-shell structures via a simple tuning of experimental factors. The IrNiCu DNF exhibited high electrocatalytic activity for oxygen evolution reaction (OER) in acidic media, which is better than Ir/C catalyst. Furthermore, IrNiCu DNF demonstrated excellent durability for OER, which could be attributed to the frame structure that prevents the growth and agglomeration of particles as well as in situ formation of robust rutile IrO2 phase during prolonged operation.
Collapse
Affiliation(s)
- Jongsik Park
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) , Seoul 02841, Korea
- Department of Chemistry and Research Institute for Natural Sciences, Korea University , Seoul 02841, Korea
| | | | - Hionsuck Baik
- Korea Basic Science Institute (KBSI) , Seoul 02841, Korea
| | - Taehyun Kwon
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) , Seoul 02841, Korea
- Department of Chemistry and Research Institute for Natural Sciences, Korea University , Seoul 02841, Korea
| | | | - Kwangyeol Lee
- Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science (IBS) , Seoul 02841, Korea
- Department of Chemistry and Research Institute for Natural Sciences, Korea University , Seoul 02841, Korea
| |
Collapse
|
10
|
Abstract
Semiconductor alloy nanowires (NWs) have recently attracted considerable attention for applications in optoelectronic nanodevices because of many notable properties, including band gap tunability. Zinc phosphide (Zn3P2) and zinc arsenide (Zn3As2) belong to a unique pseudocubic tetragonal system, but their solid solution has rarely been studied. Here In this study, we synthesized composition-tuned Zn3(P1-xAsx)2 NWs with different crystal structures by controlling the growth conditions during chemical vapor deposition. A first type of synthesized NWs were single-crystalline and grew uniformly along the [110] direction (in a cubic unit cell) over the entire compositional range (0 ≤ x ≤ 1) explored. The use of an indium source enabled the growth of a second type of NWs, with remarkable cubic-hexagonal polytypic twinned superlattice and bicrystalline structures. The growth direction of the Zn3P2 and Zn3As2 NWs was also switched to [111] and [112], respectively. These structural changes are attributable to the Zn-depleted indium catalytic nanoparticles which favor the growth of hexagonal phases. The formation of a solid solution at all compositions allowed the continuous tuning of the band gap (1.0-1.5 eV). Photocurrent measurements were performed on individual NWs by fabricating photodetector devices; the single-crystalline NWs with [110] growth direction exhibit a higher photoconversion efficiency compared to the twinned crystalline NWs with [111] or [112] growth direction.
Collapse
Affiliation(s)
- Hyung Soon Im
- Department of Chemistry, Korea University , Jochiwon 339-700, Korea
| | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
Addition of Ag is a promising way to enhance the H2 permeability of sulfur-tolerant PdCu membranes for cleanup of coal-derived hydrogen. We investigated a series of PdCuAg membranes with at least 70 atom % Pd to elucidate the interdependence between alloy structure and H2 permeability. Membranes were prepared via sequential electroless plating of Pd, Ag, and Cu onto ceramic microfiltration membranes and subsequent alloying at elevated temperatures. Alloy formation was complicated by a wide miscibility gap in the PdCuAg phase diagram at the practically feasible operation temperatures. X-ray diffraction showed that the lattice constants of the fully alloyed ternary alloys obey Vegard's law closely. In general, H2 permeation rates increased with increasing Ag and decreasing Cu content of the membranes in the investigated temperature range. Detailed examination of the permeation kinetics revealed compensation between activation energy and pre-exponential factor of the corresponding H2 permeation laws. The origin of this effect is discussed. Further analysis showed that the activation energy for H2 permeation decreases overall with increasing lattice constant of the ternary alloy. The combination of these correlations results in a structure-function relationship that will facilitate rational design of PdCuAg membranes.
Collapse
Affiliation(s)
- Lingfang Zhao
- Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Zhongshan Road 457, 116023 Dalian, China
| | | | | | | |
Collapse
|