Novel synthesis of in situ CeOx nanoparticles decorated on CoP nanosheets for highly efficient electrocatalytic oxygen evolution

CeOx as a (co-)catalyst has been proved a promising material toward the oxygen evolution reaction (OER) in water splitting. In this study, a novel two-step method for the synthesis of cerium oxide nanoparticles in-situ generatedon CoP nanosheets toward OER is presented. Interestingly, Ce ions were gradually hydrolyzed and oxidized under the action of alkaline ligand andsolvothermal environment, and eventually existed in the form of CeOx on the 2D Co-MOF nanosheets in the first step. In the followed selective phosphating process, 2D Co-MOF nanosheets act as the template are transformed into CoP nanosheets but CeOx is still maintained. Optimal CeOx/CoP nanosheets exhibit low OER overpotential, small Tafel slope and robust durability. Furthermore, in situ electrochemical Raman spectroscopy demonstrates the transformation of the active catalytic species during the oxidation process. This in situ generation of a cocatalyst and selective phosphidation strategy provides some guidelines for the designing of highly efficient catalysts for OER and even other explorations.

Automated summary

A novel two-step method for in-situ generation of cerium oxide nanoparticles on CoP nanosheets as catalyst for OER is presented in this study. The optimal CeOx/CoP nanosheets exhibit excellent OER performance, providing guidelines for the design of highly efficient catalysts.