In-situ electrochemical self-tuning of amorphous nickel molybdenum phosphate to crystal Ni-rich compound for enhanced overall water splitting
| Autor: | Liping Sun, Fanhao Kong, Lihua Huo, Hui Zhao |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Renewable Energy Sustainability and the Environment Oxygen evolution Energy Engineering and Power Technology chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Electrocatalyst 01 natural sciences 0104 chemical sciences Amorphous solid chemistry.chemical_compound Nickel Chemical engineering chemistry Water splitting Electrical and Electronic Engineering Physical and Theoretical Chemistry 0210 nano-technology Bifunctional Hybrid material Hydrogen production |
| Zdroj: | Journal of Power Sources. 430:218-227 |
| ISSN: | 0378-7753 |
| DOI: | 10.1016/j.jpowsour.2019.05.037 |
| Popis: | Developing bifunctional electrocatalyst with low-cost, high-activity, and durability towards hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is the key for large-scale hydrogen production. In this paper, a novel one-dimensional amorphous nickel molybdenum phosphate nanoarray (NiMoPOx) is prepared on nickel foam via two-step reations. NiMoPOx exhibits excellent electrocatalytic activity than the state of the art Pt/C and RuO2. For overall water splitting reaction, NiMoPOx electrode couple achieves 1.55 V at 10 mA cm−2 for prolonged 50 h operation in 1.0 M KOH. The excellent bifunctional electrocatalytic properties come from the in-situ electrochemical surface self-tuning of NiMoPOx “precatalyst”. During the self-tuning process, the surface of amorphous NiMoPOx is in-situ transformed to metallic Ni and Ni(OH)2 nanoparticles under HER and OER, leading to the formation of special heterostructure hybrid materials. Further investigations indicate that the in-situ produced metallic Ni nanoparticles favor the generatation of adsorbed H atom in water dissociation, therefore enhance the hydrogen evolution kinetics and activity. Meanwhile the in-situ formed Ni(OH)2 nanoparticles become the actual surficial species to promote oxygen evolution reaction. This self-tuning method provides a new idea to develop high-performance electrocatalysts for some sustainable energy conversion systems, such as water splitting and metal-air batteries. |
| Databáze: | OpenAIRE |
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