Cobalt/Molybdenum Phosphide and Oxide Heterostructures Encapsulated in N‑Doped Carbon Nanocomposite for Overall Water Splitting in Alkaline Media

• Published in: ACS applied materials & interfaces 2019-02, Vol.11 (7), p.6890-6899
• Main Authors: Yu, Lei, Xiao, Yun, Luan, Chenglong, Yang, Juntao, Qiao, Hongyan, Wang, Yao, Zhang, Xin, Dai, Xiaoping, Yang, Yang, Zhao, Huihui
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.8b15653

The development of designing and searching inexpensive electrocatalysts with high activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is significant to enable water splitting as a future renewable energy source. Herein, we synthesize a new CoP­(MoP)-CoMoO3 heterostructure coated by a N-doped carbon shell [CoP­(MoP)-CoMoO3@CN] via thermal decomposition and phosphatizing of the CoMoO4·0.9H2O nanowires encapsulated in N-doped carbon. At 10 mA·cm–2, this CoP­(MoP)-CoMoO3@CN nanocomposite exhibits superior electrocatalytic activity at low overpotentials of 296 mV for OER and 198 mV for HER in alkaline media. More importantly, we achieve a current density of 10 mA·cm–2 at 1.55 V by using this CoP­(MoP)-CoMoO3@CN as both cathode and anode for overall water splitting. This promising performance could be due to the high activity of CoP­(MoP)-CoMoO3 and the good conductivity of the external mesoporous N-carbon shell, which makes the CoP­(MoP)-CoMoO3@CN nanowires a competitive alternative to noble-metal-based catalysts for water splitting.