The mechanism and surface engineering of carbon encapsulate defects-rich molybdenum phosphide for the hydrogen evolution reaction in alkaline media
| Autor: | Bitao Liu, Chong-Geng Ma, Lingling Peng, Jun Wang, Fu Junchao, Lei Zhao, Zhi-Jian Fu, Wenbo Chen, Jianbei Qiu, Dedan Mou, Qinping Qiang, Jumeng Wei |
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| Rok vydání: | 2021 |
| Předmět: |
Tafel equation
Materials science Phosphide Mechanical Engineering Metals and Alloys 02 engineering and technology Overpotential 010402 general chemistry 021001 nanoscience & nanotechnology Electrocatalyst 01 natural sciences Dissociation (chemistry) 0104 chemical sciences Catalysis Metal chemistry.chemical_compound Chemical engineering chemistry Mechanics of Materials visual_art Materials Chemistry visual_art.visual_art_medium Water splitting 0210 nano-technology |
| Zdroj: | Journal of Alloys and Compounds. 850:156737 |
| ISSN: | 0925-8388 |
| Popis: | Inexpensive metal-based electrocatalyst with excellent stability and activity for efficient hydrogen evolution reaction is the most critical issue for large-scaled water splitting. However, the electricity kinetics in alkaline is relatively sluggish than in acid owing to the concentration of protons in alkaline is low. Thus, accurate structural designs to obtain more protons in the water dissociation on the surface of catalyst are necessary. In this work, a defect-rich MoP is encapsulated with carbon shell, which precisely regulated to distinguish the affection on hydrogen evolution reaction. The synergistic effect between carbon shell and defective sites is identified by the free energy and charge distribution density for water/hydrogen adsorption in hydrogen evolution via a density functional theory calculation. The results show that the lattice defects and the carbon shells play a unique role in enhancing catalytic performance, which the lattice defects decide the active sites and the thinner carbon shell would enhance its activity. The optimal overpotential in alkaline media of this designed MoP/C is 100 mV at 10 mA cm−2, its Tafel slope is 67.4 mV dec−1, and also exhibits a long-term stability for 12 h. |
| Databáze: | OpenAIRE |
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