Advanced materials for high-performance electrochemical water-splitting: a review of recent breakthroughs, and future prospects

The sluggish HER/OER kinetics and the lack of dependable, highly efficient electrocatalysts limit the large-scale use of electrochemical water splitting, despite its potential as a sustainable hydrogen generating technique. This review presents comprehensive and mechanistically informed evaluation of the advanced electrocatalysts with particular emphasis on non-noble metal-based systems, including nanostructure surfaces, layer double hydroxides (LDH), metal-organic frameworks (MOFs), high-entropy materials (HEMs), perovskites, graphene-based materials, and covalent-organic frameworks (COFs). This review provides a unified framework for structure, property, and performance by correlating the strategies for the catalysts design, such the heteroatom doping, defect engineering, and the hybrid interface construction, with that of the key performance metrics including the current density, stability, cell voltage, and overpotential. Additionally, the influence of the operating conditions is also considered to offer more realistic perspective on the performance of the catalysts across the different electrochemical environments. Through the critical evaluation of the recent advancements, this review identifies key trends governing the catalytic behavior including the role of the active site engineering, interfacial effects, and the modulation of the electronic structure. This review outlines the actionable strategies which are aimed at bridging the gap between the laboratory-scale studies and the industrial water splitting, thus offering a rational framework for the development of the next-generation electrocatalysts for sustainable hydrogen production.