The kinetics and potential dependence of the hydrogen evolution reaction optimized for the basal-plane Te vacancy site of MoTe₂
Abstract
Electrocatalysis at the edge sites of transition-metal dichalcogenides has been well studied, particularly for the hydrogen evolution reaction (HER). Here, we explore instead the HER activity on the basal plane of MoTe₂ by creating anion vacancies via computational predictions followed by experimental validation. Using the grand canonical potential kinetics method, we predict that overpotentials of 535 and 565 mV can achieve a current density of 10 mA cm⁻² for 1T′-MoTe₂ and 2H-MoTe₂ containing 1.14 x 10¹⁴ cm⁻² and 3.45 x 10¹³ cm⁻² Te vacancies, respectively. This is in good agreement with experimental overpotentials of 561 and 634 mV for 1T′-MoTe₂ and 2H-MoTe₂ containing similar vacancies ( 1.28 x 10¹⁴ cm⁻² and 3.54 x 10¹³ cm⁻², respectively). Furthermore, we used Ar plasma treatment to increase the Te vacancy on the basal plane and found an optimal vacancy concentration of 3.18 x 10¹⁴ cm⁻² for 1T′-MoTe₂ and 1.02 x 10¹⁴ cm⁻² for 2H-MoTe₂. Increasing or decreasing the vacancy concentrations from this level further reduces HER performance.
Additional Information
© 2022 Elsevier. The authors acknowledge funds from the Research Grant Council of Hong Kong SAR (16304518), NSFC-RGC Joint Research Scheme (N_HKUST607/17), Zhongshan City Bureau of Science and Technology (2019AG018), IER Foundation (HT-JD-CXY-201907), "International science and technology cooperation projects" of the Science and Technological Bureau of Guangzhou Huangpu District (2019GH06), Guangdong Science and Technology Department (project 2020A0505090003), and Research Fund of the Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology (2020B1212030010). Technical assistance from Dr. Yuan Cai in the Materials Characterization and Preparation Facilities of the Hong Kong University of Science and Technology is greatly appreciated. W.A.G. was supported by the Liquid Sunlight Alliance, which is supported by the Fuels from Sunlight Hub (award DE-SC0021266) of the Basic Energy Sciences program of the US Department of Energy Office of Science. The authors gratefully acknowledge Dr. Yufeng Huang and Dr. Soonho Kwon for valuable discussions. The calculations were performed on computer clusters at the Caltech Materials and Process Simulation Center, the Caltech High-Performance Computing Center, and the HKUST (funded by the School of Engineering). Author contributions. M.D.H. and Z. Liu contributed equally. M.D.H., Z. Liu, W.A.G., and Z. Luo conceived the idea and designed the research. M.D.H. performed all the calculations and data collection. M.D.H., A.T., and F.R. participated in discussions analyzing the data obtained from the calculations. Z. Liu performed syntheses, characterization, and electrochemical testing. Z. Liu, H.L., J.L., M.A., and Y.C. helped in collecting data during synthesis, characterization, and electrochemical testing. M.D.H., Z. Liu, W.A.G., and Z. Luo wrote the paper with helpful comments from all authors. W.A.G. and Z. Luo supervised this project. Data and code availability. The data and code that support the findings of this study are available from the lead contact upon request. The authors declare no competing interests.Additional details
- Eprint ID
- 119609
- Resolver ID
- CaltechAUTHORS:20230301-701033500.9
- 16304518
- Research Grants Council of Hong Kong
- N_HKUST607/17
- National Natural Science Foundation of China
- 2019AG018
- Zhongshan City Bureau of Science and Technology
- HT-JD-CXY-201907
- IER Foundation
- 2019GH06
- Science and Technological Bureau of Guangzhou Huangpu District
- 2020A0505090003
- Guangdong Science and Technology Department
- 2020B1212030010
- Guangdong-Hong Kong-Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology
- DE-SC0021266
- Department of Energy (DOE)
- Created
-
2023-05-12Created from EPrint's datestamp field
- Updated
-
2023-05-27Created from EPrint's last_modified field
- Caltech groups
- Liquid Sunlight Alliance
- Other Numbering System Name
- WAG
- Other Numbering System Identifier
- 1555