Current Advancement in Benchmarking Stable Water Splitting Electrocatalysts: A Chemist Perspective

Electro-induced water splitting module is a fascinating strategy for the conversion of electricity into scalable and clean H2 as a future energy carrier and has significantly attracted the attention of the scientific community. However, despite countless research, cost-effective and durable electrode materials with high conversion efficiency remain a challeng in this quest. This critical review is devoted to systemically presenting the upsurge of recently explored highly stable benchmark electrocatalysts (both noble and non-noble) to understand the design principles, performances, mechanistic studies, and compelling reasons/chemistry behind the ameliorated catalytic potential over traditional electrocatalysts for half-cell oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Moreover, the highly stable electrode materials (at least ≥ 50 h) and their bi-functional conduct evaluated in prototype electrolyzer (two electrode systems) integrated with photovoltaic PV or batteries at the laboratory level are discussed, yet an untold and unsummarized story in electrochemical water splitting. Next, the current status of this technology, socio-economic challenges, possible solutions, and fundamental principles/concepts behind the water splitting conversion scheme is outlined from the point of practical application. Typical challenges remain regarding identifying, preparing, and scaling the potential electrocatalysts, but the foundations are now strong, and the outlook is visible for this exciting next-generation technology.