Recent trends in electrochemical catalyst design for hydrogen evolution, oxygen evolution, and overall water splitting

•Synthesis and characterization of water splitting catalysts.•Hydrogen evolution catalysts in acidic, alkaline, and neutral media.•Oxygen evolution catalysts in acidic, alkaline, and neutral media.•State-of-the-art catalysts for overall water splitting in different media.•Requirements and outlook of catalyst development for water splitting. There is a significant and rapidly increasing interest in the scientific and public communities toward the reduction of the global reliance on fossil fuels. The use of H2 generated by electrochemical water splitting is one potential strategy for meeting this goal. Due to this heightened interest, many research articles are published annually on various catalysts ranging from metals, bimetallics, metal-oxides, doped metal-oxides, metal organic frameworks, non-metals, etc. Herein, we examine a wide variety of recently published literature on the development of novel catalysts for electrochemical water splitting. This includes common techniques for the synthesis of these catalysts, analyzing trends in the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting (OWS) in acidic, basic, and neutral media. A further meta-analysis of the common issues encountered in the field and future outlooks are discussed. [Display omitted]