Extending available body space loading active species and controllably tailoring the d‐band center to Fermi level of catalysts are of paramount importance but extremely challenging for the enhancement of electrocatalytic performance. Herein, a melamine‐bridged self‐construction strategy is proposed to in situ embed Co‐based bimetallic nanoparticles in the body of N‐doped porous carbon spheres (CoM‐e‐PNC), and achieve the controllable tailoring of the d‐band center position by alloying of Co and another transition metal M (M = Ni, Fe, Mn, and Cu). The enrichment and exposure of the active sites in the body interior of porous carbon spheres, and the best balance between the adsorption of OH species and the desorption of O2 induced by optimizing the d‐band center position, collectively enhance the oxygen evolution reaction (OER) performance. Meanwhile, the relationship of d‐band center position and OER activity is found to exhibit the volcano curve rule, where the CoNi‐e‐PNC catalyst shows optimal OER performance with an overpotential of 0.24 V at 10 mA cm−2 in alkaline media, outperforming those of the ever‐reported CoNi‐based catalysts. Besides, CoNi‐e‐PNC catalyst also demonstrates high OER stability with slight current decrease after 100 h.

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.

The search for Earth-abundant and efficient electrode materials is significant for advanced supercapacitors.

Ever-increasing energy crises require the exploration of sustainable energy conversion and storage systems that are reliable, low-cost and environmentally friendly. The search for Earth-abundant and efficient electrode materials is significant for advanced supercapacitors. Transition metal chalcogenides has regarded as one of the most emerging new materials for electrochemical energy storage device. Manganese diselenide is a low-cost and eco-friendly semiconducting material with applications in lithium ion battery and oxygen reduction catalysis. However, there have been fewer reports on the electrochemical performance research of manganese diselenide. In this study, cubic manganese diselenide (MnSe2) were synthesized by using a one-pot hydrothermal method. Physicochemical characterizations revealed the formation mechanism of MnSe2 nanosheets. Electrochemical analysis suggested the pseudocapacitive nature of MnSe2 electrode, which delivered a specific capacitance of 423 F g-1 at a current density of 1 A g-1, and obtained 203 F g-1 at 30 A g-1. The superior electrochemical performance of MnSe2 nanosheets highlights the potential use as electrode material in supercapacitor.