Ce doped Co(PO3)2@NF bifunctional electrocatalyst for water decomposition

Abstract

Efficient hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalysts have attracted an increasing attention in the hydrogen production by electrolysis of water because of their prominent electrocatalytic activity. Many previous researchers have illustrated that metal cation doping is conducive to promoting the charge transfer, optimizing the adsorption/desorption rate of intermediates via adjustment of the electronic structure, thus accelerating the reaction kinetics. In this work, Ce doped Co(PO3)2@NF nanosheets in-situ grow onto the nickel foam (NF) substrate to obtain a new bifunctional catalyst. The catalytic performance against HER and OER of Ce-Co(PO3)2 was significantly improved due to the Ce doping. In 1.0 M KOH solution, the overpotentials of HER and OER are 81 mV and 286 mV (10 mA cm−2), respectively. Compared with Co(PO3)2 (η10 = 128 mV (HER) and η10 = 376 mV (OER)), the catalytic performance has been significantly improved. Most importantly, the electrolyser acquires a lower cell voltage of 1.56 V at 10 mA cm−2 with a small current density attenuation in continuous electrolysis for 24 h. This work demonstrates that transition metal Ce doping is a valid method to rationally design bifunctional non-noble metal catalysts.