ZIF-67-derived nickel–cobalt phosphide nanocubes/N-doped carbon/nickel form composite for efficient overall water splitting

Abstract

Hydrogen production from electrochemical water splitting is a promising strategy to generating green energy, which requires development of efficient and stable bifunctional catalysts for hydrogen and oxygen evolution reaction (HER/OER). Herein, dual transition metal phosphides/N-doped carbon/Nickel foam composite (CoNiP/NC-NF) is prepared via direct phosphidation of ZIF-67, in which ZIF-67 can control the size and N-doping content of CoNiP/NC, boosting the bifunctional activities for the OER and HER. Then, the overall water splitting is performed by using CoNiP/NC-NF as the cathode and anode, showing a low cell voltage of 1.60 V to reach current density of 10 mA cm−2. Experimental studies indicate that ZIF-67 influences the electrocatalytic performance, and theoretical studies identify the active component of CoNiP/NC-NF for HER and OER, respectively.