Interfacial engineering of metal–organic framework derived hierarchical CoP–Ni5P4 nanosheet arrays for overall water splitting

Abstract

To sustainably develop an economical, efficient and stable non-noble metal hydrogen production catalyst is still an essential challenge. Herein, a hierarchical CoP–Ni₅P₄ nanosheet array self-supported electrode (CoP–Ni₅P₄/NF) for water splitting was successfully constructed by a simple MOF calcination method. CoP–Ni₅P₄/NF exhibited outstanding performance for overall alkaline water splitting, and the potential is only 1.47 V at 10 mA cm⁻² with outstanding stability beyond 50 h. Combining the experimental analyses and theoretical calculations, it is revealed that the construction of the hierarchical CoP–Ni₅P₄ nanosheet array self-supported electrode increases the exposure of active sites and enhances the conductivity and stability. Moreover, the interfacial effect of CoP–Ni₅P₄ effectively regulates the electronic structure and reduces the adsorption energy of intermediates, thus improving water electrolysis kinetics. This work provides fresh impetus to the design of MOF-derived two-dimensional heterogeneous catalysts for overall water splitting.