Unveiling the significance of working electrode substrates in electrocatalytic water splitting for sustainable hydrogen energy production

Abstract

The chemical and physical properties of the current collector (working as a catalyst support) have crucial effects on the performance of electrocatalysts as it acts as a bridge for transferring electrons among the various parts of an electrochemical system. Therefore, the proper selection of the current collector or substrate for drop-casting, coating, or in situ growth of active electrocatalysts and an in-depth understanding of their behaviour under experimental conditions are very crucial. This perspective summarizes the significance of various working electrode (WE) substrates in terms of their performance towards water electrolysis, which involves the anodic oxygen evolution reaction (OER) and the cathodic hydrogen evolution reaction (HER). From this perspective, various aspects of commonly employed WE substrates (metallic or non-metallic) are scrutinized in detail. This perspective starts with an introduction to hydrogen technology, followed by a discussion on the kinetics and mechanism of two half-cell reactions in water electrolysis and various chemical and physical factors influencing the suitability and stability of WEs for sustainable green hydrogen production via water electrolysis. Overall, this report presents a promising avenue to unmask the significance of the substrate choice for advancing electrocatalytic water splitting towards sustainable hydrogen production.