Graphene oxide supported transition metal mixed oxide nanourchins onto bimetallic phosphide coatings as high performance hydrogen evolution electrodes in alkaline media

Abstract

Recently, electrocatalyst with high reactivity and stability towards hydrogen evolution reactions are necessary for large scale high purity hydrogen production to resist upcoming energy crisis. The transition metal mixed oxide based HER electrocatalyst are promising candidates for hydrogen generation in renewable energy field due to their low-cost nature, ease of commercialization and green nature. Herein, graphene oxide supported MnO2-TiO2 nanourchins synthesized by thermal decomposition technique was incorporated to bimetallic phosphide ENCP coatings by electroless plating technique. During alkaline hydrogen evolution, the incorporation of composite onto bimetallic phosphide causes a drastic decreases in overpotential value to 190 mV dec−1 and respective Tafel slope value to 45 mV dec−1. The studies reveals that the modified electrode follows Volmer–Heyrovsky mechanism. The lower Rct of 140.8 Ω and a high Cdl value obtained from Nyquist plot of modified electrodes ensures the fastest electron transfer kinetics and confirms its more facile electrocatalytic nature towards hydrogen evolution. Also, a high value for exchange current density of modified electrode authenticate its superior HER performance. The modified electrodes was durable, long term stable, economically viable and performance was consistent over a wide span of time during alkaline hydrogen evolution reaction. The enhanced performance of modified electrode can be ascribed to the intermetallic synergetic effect arises within ENCP matrix and MnO2-TiO2 nanourchins. These conclusions lead to innovative insights on future perspective for the development and tuning of novel electrocatalysts with enhanced electrochemical performance for hydrogen evolution reaction.