Co2Mo3O8/Nb2O5 heterojunctions with rich oxygen vacancies wrapped in cobalt embedded carbon hollow cubic nanoboxes greatly improves the oxygen evolution performance and stability for water splitting

作者：Ye, Leijun; Zheng, Hui; Jiang, Zhong-Jie; Jiang, Zhongqing^*

来源：Journal of Alloys and Compounds, 2023, 963: 171266.

DOI：10.1016/j.jallcom.2023.171266

• Heterojunction
• Oxygen vacancies
• Carbon hollow cubic nanoboxes
• Electron coupling interaction
• Oxygen evolution reaction

Herein, Co2Mo3O8/Nb2O5 heterojunctions with rich oxygen vacancies wrapped in cobalt embedded carbon hollow cubic nanoboxes (Co(Mo,Nb)@MCNBs) derived from metal-organic frameworks (MOFs) is synthesized by hydrothermal reaction, bimetallic cation doping, high-temperature carbonization. The synergistic effect and strong electron coupling interaction between Co2Mo3O8/Nb2O5 heterojunctions and cobalt embedded carbon hollow cubic nanoboxes result in a more uniform distribution of heterojunctions on the surface of Co@MCNBs, more catalytic active sites are exposed and the catalytic performance is improved. It only requires an over -potential of 284 mV to drive the current density of 10 mA cm-2 towards oxygen evolution reaction (OER), which is significantly lower than most previously reported catalysts and commercial RuO2. Furthermore, the Co(Mo,Nb) @MCNBs exhibits exceedingly good long-term stability with the current density retention rate of 98.1% after 43,200 s for OER, which even still outperform the commercial RuO2 catalyst. More interestingly, the electrolyzer Co(Mo,Nb)@MCNBs(+)||Co@MCNBs(-) demonstrates an excellent cycling stability and outperforms RuO2(+)|| Pt/C(-), suggesting the actual availability of Co(Mo,Nb)@MCNBs in overall water splitting. The synergic effect of heterostructures design of the Co(Mo,Nb)@MCNBs catalyst for overall water splitting will promote the mass production of hydrogen with high-efficiency and low-cost.