Modulating the electronic configuration of Co species in MOF/MXene nanosheet derived Co-based mixed spinet oxides for an efficient oxygen evolution reaction

作者：Xu, Chuming; Yang, Xifeng; Li, Shuang^*; Li, Keke; Xi, Benjun; Han, Qing-Wen; Wu, Ya-Pan; Wu, Xue-Qian; Chi, Ru-an; Li, Dong-Sheng^*

来源：Inorganic Chemistry Frontiers, 2022, 10(1): 85-92.

DOI：10.1039/d2qi02098j

• WATER OXIDATION
• CO3O4
• CO2TIO4
• SITES

The electronic configuration of Co cations at octahedral (Oct) sites Ways a crucial role in the catalytic activity of Co3O4-based spinet oxides toward the oxygen evolution reaction (OER). However, there are few reports on modulating the electronic configuration of partial Co-Oct(3+) (t(2g)(6) e(g)(0)) to Co-Oct(2+) (t(2g)(6) e(g)(1)) for further promoting their OER performances. Herein, a metal-organic framework (MOF)/MXene composite material pyrolysis-reorganization strategy is developed to obtain heterogeneous Co-based mixed spinet oxides, Co3O4/Co2TiO4. By regulating the pyrolysis temperature, the mesoporous structures and the electronic configuration of Co-Oct cations of mixed spinet oxides can be simultaneously optimized, leading to exceptional OER performances with low overpotentials of 280 mV on a glassy carbon electrode and 260 mV on Ni foam at 10 mA cm(-2) as well as good stability in alkaline solution. The synergistic catalytic effect between Co-Oct(3+) in Co3O4 and Co-Oct(2+) in Co2TiO4 is shown to be crucial for improving the OER activity. This finding will provide a new pathway for promoting the OER activity of Co-based spinet oxides.