NiSe@Ni12P5 hierarchical nanorod arrays coupled on nickel-copper foam for highly efficient urea oxidation

Abstract

Electrocatalytic urea oxidation reaction (UOR) is one of the most promising energy-saving alternatives to anodic oxygen evolution reaction (OER), and the development of efficient and stable catalysts for UOR is crucial. Therefore, in this paper, hierarchical structure NiSe@Ni12P5/NCF with Ni12P5 nanorod arrays coupled with NiSe nanospheres are synthesized on bare nickel-copper foam (NCF) by exogenous phosphorylation and subsequent electrodeposition methods. The catalytic performance of hierarchical structure NiSe@Ni12P5/NCF in urea-assisted electrolytic water reaction is studied in focus. The results show that the potential of NiSe@Ni12P5/NCF was only 1.267 V and 1.412 V vs RHE at current densities of 10 mA cm−2 and 100 mA cm−2, respectively, in addition to no significant activity decay after 140 h stability test. This is attributed to the fact that the introduction of NiSe regulated the interfacial charge distribution, creating an interfacial coupling effect that can greatly increase the original catalytic species, as well as the NiOOH species generated during the UOR process as true active sites, which ultimately improving the electrocatalytic UOR performance of NiSe@Ni12P5/NCF. This study provides a new idea for the preparation of hierarchical selenide - phosphides for electrochemical applications.