The odyssey of cobaloximes for catalytic H2 production and their recent revival with enzyme-inspired design.

Cobaloxime complexes gained attention for their intrinsic ability of catalytic H2 production despite their initial emergence as a vitamin B12 model. The simple, robust, and synthetically manoeuvrable cobaloxime core represents a model catalyst molecule for the investigation of optimal conditions for both photo- and electrocatalytic H2 production catalytic assemblies. Cobaloxime is one of the rare catalysts that finds equal applications in the analysis of homogeneous and heterogeneous catalytic conditions. However, the poor aqueous solubility and long-term instability of cobaloximes have severely impeded their growth. Lately, interest in the cobaloxime-based catalysts has been resuscitated with the rational use of extended enzymatic features. This unique enzyme-inspired catalyst design strategy has instigated the formation of a new genre of cobaloxime molecules that exhibit enhanced photo- and electrocatalytic H2 evolution with improved aqueous and air stability.