Cobalt-based spinel oxide is a promising electrocatalyst for oxygen evolution reaction (OER) because of its low cost, excellent activity and stability. Herein, we designed the CuMn x Co 2 O 4 electrocatalyst with tunable electronic structure via Mn-doping to enhance OER performance. Results showed that the CuMn 0.5 Co 2 O 4 catalyst prepared by calcined at 600°C exhibited high crystalline without impurity phase, and possessed the enhanced Co 2 + /Co 3 + ratio and high concentration of oxygen vacancies, which were facilitated to enhance OER performance. Electrochemical test results showed the CuMn 0.5 Co 2 O 4 catalyst had high OER performance with a low overpotential of 340 mV at the current density of 10 mA • cm À 2 and a smaller Tafel slope of 69.8 mV • dec À 1 . TOF and ECSA results illustrated that the more intrinsic catalytic activity on the CuMn 0.5 Co 2 O 4 catalyst. After 1000 cycles, the catalyst exhibited high stability with the 8 1.7 % of current retention rate. The OER activity enhancement mechanism of was further analyzed, which were mainly ascribed to the conversion of variable Co 2 + / Co 3 + and enhanced oxygen vacancies.

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Energy storage devices(ESDs) need to design and develop high electrochemical performance and promising electrode materials. Transition-metal chalcogenides(TMCs) are being actively investigated as the electrode for electrochemical ESDs. Herein, we report...