Hierarchical growth of vertically standing Fe3O4-FeSe/CoSe2 nano-array for high effective oxygen evolution reaction

Large-scale electrochemical water splitting is hindered by the sluggish oxygen evolution reaction (OER) kinetics. In this work, we report a vertically standing Fe 3 O 4 -FeSe/CoSe 2 hierarchical structure material grown on carbon cloth as a highly active OER electrocatalyst . Benefiting from the rock-like Fe 3 O 4 particles on the carbon cloth, the CoSe 2 nano-arrays are more firmly affixed onto the carbon cloth. In addition, small amount of FeSe particles adsorbed on the CoSe 2 arrays offer a synergistic advantage, in which CoSe 2 achieved a small 279 mV overpotential at a current density of 10 mA cm −2 and a low Tafel slope of 68.78 mV dec −1 . By comparing the performance of Fe 3 O 4 -FeSe/CoSe 2 with pure CoSe 2 and Fe 3 O 4 -FeSe, it demonstrates to be the most efficient OER catalyst. Significantly, the hierarchical structural strategy of fixed Fe 3 O 4 growth on carbon cloth arrays introduces a new concept to explore the design of high efficiency OER electrocatalysts.