Amorphous three-dimensional porous Co3O4 nanowire network toward superior OER catalysis by lithium-induced

Abstract

Co3O4 has been proven to be a potential catalyst for oxygen evolution reaction (OER) because of its low cost and abundant resources. However, pure Co3O4 has the disadvantages of poor conductivity and low catalytic activity. Here, we successfully synthesized three-dimensional (3D) network Co3O4 composed of nanowires grown on nickel foam (NF). Using a lithium-ion rocking chair transport mechanism, Co3O4 nanowires were transformed into porous amorphous Co3O4, which greatly reduces the resistance in the OER process and enhances active site exposure. Meanwhile, the increase of Co2+ greatly improved the OER performance. However, excessive cycling of lithium-ion batteries can form a thick solid electrolyte interface (SEI) on the surface, which has a negative impact on OER. Specifically, we found that 5-cycle Co3O4 has the best OER performance, showing an initial potential of 1.42 V vs RHE, a reduced overpotential of 311 mV at 50 mA cm−2 and a low Tafel slope of 76 mV decade−1, which is better than commercial RuO2.