An overview on advances in design and development of materials for electrochemical generation of hydrogen and oxygen

Abstract Water splitting technology is the most promising, low-cost, and green technology for many innovative energy devices such as electrolyzers, fuel cells, metal-air batteries, etc. Designing and developing earth-abundant, low-cost, and highly efficient electrocatalysts is crucial for commercializing water-splitting technology. In the last couple of years, various nanostructure electrocatalysts have been reviewed. However, most catalysts go through fewer active sites, instability, and other deficiencies. For enhancing the activity, various immerging strategies such as decreasing the layer thickness, creating crystal defects, forming the composite, doping heteroatoms, etc., have been developed. Therefore, it is highly demanding to summarize the existing data, which could afford a conclusive track for the thriving research of electrocatalysts towards water splitting. Instead of focusing on a special strategy for improving the catalytic activity, we present a relatively comprehensive review of the recent research progress on various immerging strategies. We have systematically discussed the fundamental science regarding water splitting and different electrochemical parameters for hydrogen and oxygen evolution reactions. The computational and experimental approaches for the recent advancement of catalytic activity developed in the current year have been discussed and investigated. Finally, the outlook of the water-splitting technology has been summarised.