Exploring the Progress and Mechanisms of Hydrogen Evolution Catalyzed by Cobaloximes: A Comprehensive Review

In recent years, significant progress has been made in the development of cobalt diamine-dioxime complexes, which have emerged as promising molecular catalysts. These catalysts offer several advantages, including enhanced stability against hydrolysis and versatility in various reaction conditions. Through derivatization of the ligand at the hydrocarbon chain connecting the two imine functions, the cobalt diamine-dioxime catalyst can be conveniently coupled with surfaces or photosensitizers. This modification provides a more efficient approach compared to the original cobaloximes. Notably, the cobalt diamine-dioxime catalyst has demonstrated activity in H2 evolution under fully aqueous conditions, both when immobilized onto electrode materials and in light-driven homogeneous conditions. These remarkable properties create opportunities for the construction of molecular-based photocathodes, serving as a critical component in dye-sensitized photoelectrochemical cells.