Surface electron accumulation and enhanced hydrogen evolution reaction in MoSe2 basal planes
| Autor: | H.Y. Du, Y.W. Chu, Kuei-Hsien Chen, H.R. Chen, C.M. Cheng, Y.T. Huang, Y.S. Chang, Ruei-San Chen, Li-Chyong Chen, L.C. Chao, Tsu Yi Fu, C.Y. Chen, K.Y. Lee, S.W. Ke, C.J. Ho |
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| Rok vydání: | 2021 |
| Předmět: |
Tafel equation
Materials science Renewable Energy Sustainability and the Environment Analytical chemistry 02 engineering and technology Conductivity Overpotential 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences Exfoliation joint 0104 chemical sciences Catalysis chemistry.chemical_compound chemistry Molybdenum diselenide General Materials Science Electrical and Electronic Engineering Thin film 0210 nano-technology |
| Zdroj: | Nano Energy. 84:105922 |
| ISSN: | 2211-2855 |
| Popis: | The spontaneous formation of surface electron accumulation (SEA) was observed in synthesized molybdenum diselenide (MoSe2) layered crystals with two-hexagonal (2 H) structure. An anomalously high electron concentration at the surface up to 1019 cm−3 is several orders of magnitude higher than that (3.6 × 1012 cm−3) of the inner bulk. The SEA is found to be generated easily by mechanical exfoliation and room temperature deselenization. Se-vacancies have been confirmed to be the major source resulting in SEA and n-type conductivity, and also the active sites for electrochemical catalysis in MoSe2. Noted that the SEA conjugated with the Se-vacancy-related surface defects enhances the electrochemical hydrogen evolution reaction (HER) activity substantially. The optimized HER efficiency with an overpotential at 0.17 V and Tafel slope at 60 mV/dec of the basal plane of 2 H-MoSe2 was achieved by the nitrogen plasma treatment, which has outperformed several nanostructures, thin films, and hybrid counterparts. This study reveals the intriguing surface-dominant electronic property and its effect on the HER enhancement of the basal plane, which is crucial for development of a stable, low-cost and highly efficient catalyst using 2 H-MoSe2. |
| Databáze: | OpenAIRE |
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