Advanced energy materials: Current trends and challenges in electro- and photo-catalysts for H2O splitting

Current H2 production systems mainly rely on the steam reformation of fossil fuels, whereby CO2 and H2 are generated by exhausting their finite source in industry. In this paper, the development of dynamic, highly stable, and cost-effective electro- and photo-catalysts as energy materials crucial for achieving electro- and photo-catalytic H2 production from water splitting is investigated in terms of engineering chemistry. Thus, the motivation of this review is to discuss the fundamental physics of water splitting and the recent progress in the design and construction of energy materials based on metal-based catalysts (e.g., noble metals, transition metals, metal oxides, and metal sulfides) along with exceptional nanomaterials such as metal–organic frameworks and carbonaceous catalysts. Lastly, this review outlines the future challenges and scope to enable the design of active and robust energy materials for hydrogen and oxygen evolution reactions and to thereby promote the efficient production of H2 from water-splitting electrolysis.