Universal synthesis of coral-like ternary MOF-derived sulfides as efficient OER electrocatalysts

Abstract

The strategy of synthesizing high-efficiency oxygen evolution reaction (OER) catalysts using sacrificing metal–organic framework (MOF) templates is considered promising. However, few reports have focused on improving the intrinsic electrocatalytic activity of the MOF templates. Herein, we have developed a universal synthesis method for synthesizing a series of ternary coral-like FeNiM (M = Zn, Co and Cd) MOF templates. Benefitting from the synergistic effect, these trimetallic templates exhibit identical morphologies and outstanding OER performance compared to mono-metal templates. Moreover, transition metal sulfides (FeNiZnS) have been synthesized to enhance the overall electrical conductivity of catalyst materials. Optimized FeNiZnS-1 exhibits a minimal overpotential of 249 mV to achieve a current density of 10 mA cm⁻², alongside outstanding electrochemical durability over 60 h in chronopotentiometry (CP) testing. The two-electrode couple FeNiZnS-1//Pt/C achieves a cell voltage of 1.54 V at 10 mA cm⁻² for overall water splitting in 1 M KOH solution.