In situ electrodeposition of Pt into a trimetallic MOF composite electrode and its application in water splitting

Abstract

High current density and low cost are key considerations in the design of new electrolytic water catalytic materials. Herein, ternary metal–organic framework (MOF) arrays with a coral-like nanostructure are constructed via solvothermal growth and in situ electrochemical deposition methods. The excellent gas transfer capability of self-supported electrodes and the synergistic effect between transition metals contribute to the stable operation of the composite electrodes at high current densities. The results demonstrate that FeNiCo/NF and FeNiCoPt/NF exhibit remarkable OER (262 mV at 100 mA cm⁻²) and HER performance (218 mV at 100 mA cm⁻²). The two-electrode system (FeNiCo/NF||FeNiCoPt/NF) only requires a terminal voltage of 1.70 V to drive the overall water splitting reaction to a current density of 100 mA cm⁻², with electrochemical stability maintained for over 100 h.