Material libraries for electrocatalytic overall water splitting

Water electrolysis plays a crucial role among the strategies for hydrogen generation to replace the conventional fossil fuels. Many efforts have been devoted to developing efficient electrocatalysts for the water electrolysis process. The exploration of suitable catalytic materials with low overpotential, fast kinetic, and good electrochemical stability is actively pursued for both hydrogen and oxygen evolution reaction (HER/OER) as well as overall water splitting. Today’s hydrogen economy keeps on being driven by the characteristics of electrocatalytic materials. In this review, recent advancements achieved in electrocatalysts of water electrolysis are overviewed together with some strategies for performance improvements, such as nanoarchitecturing, heteroatomic doping, surface modulation and interface engineering. Furthermore, some of the latest achievements in the fabrication of electrode materials as practical demonstration on their viability are also discussed. With better understanding on these topics, the rationales behind their enhanced electrochemical performances are revealed and explained. Last but not least, the existing challenges and opportunities are briefly proposed for future upgradation of the water splitting performance.