Development and advancement of iridium(III)-based complexes for photocatalytic hydrogen evolution

Among the vast array of transition metal complexes which have been previously reported, organometallic compounds based on iridium(III) and relevant metal complexes have been shown to possess particularly interesting features; including a wide range of versatile chemical structures, unique photophysical properties and, perhaps most importantly, outstanding photocatalytic capabilities. This review surveys the design and evaluation of these compounds as photocatalysts/photosensitizers in systems for photocatalytic hydrogen evolution (PHE) reactions. Photo-redox mechanisms are addressed, and structure-catalytic activity relationships are identified to guide the future design of more efficient and robust photocatalytic systems.