Recent Trends in Transition Metal Phosphide (TMP)-Based Seawater Electrolysis for Hydrogen Evolution

Large-scale hydrogen (H2) production is an essential gear in the future bioeconomy. Hydrogen production through electrocatalytic seawater splitting is a crucial technique and has gained considerable attention. The direct seawater electrolysis technique has been designed to use seawater in place of highly purified water, which is essential for electrolysis, since seawater is widely available. This paper offers a structured approach by briefly describing the chemical processes, such as competitive chloride evolution, anodic oxygen evolution, and cathodic hydrogen evolution, that govern seawater electrocatalytic reactions. In this review, advanced technologies in transition metal phosphide-based seawater electrolysis catalysts are briefly discussed, including transition metal doping with phosphorus, the nanosheet structure of phosphides, and structural engineering approaches. Application progress, catalytic process efficiency, opportunities, and problems related to transition metal phosphides are also highlighted in detail. Collectively, this review is a comprehensive summary of the topic, focusing on the challenges and opportunities.