Epitaxially Grown Ru Clusters-Nickel Nitride Heterostructure Advances Water Electrolysis Kinetics in Alkaline and Seawater Media

The epitaxial heterostructure can be rationally designed based on the in situ growth of two compatible phases with lattice similarity, in which the modulated electronic states and tuned adsorption behaviors are conducive to the enhancement of electrocatalytic activity. Herein, theoretical simulations first disclose the charge transfer trend and reinforced inherent electron conduction around the epitaxial heterointerface between Ru clusters and Ni3N substrate (cRu-Ni3N), thus leading to the optimized adsorption behaviors and reduced activation energy barriers. Subsequently, the defect-rich nanosheets with the epitaxially grown cRu-Ni3N heterointerface are successfully constructed. Impressively, by virtue of the superiority of intrinsic activity and reaction kinetics, such unique epitaxial heterostructure exhibits remarkable bifunctional catalytic activity toward electrocatalytic OER (226 mV @ 20 mA cm(-2)) and HER (32 mV @ 10 mA cm(-2)) in alkaline media. Furthermore, it also shows great application prospect in alkaline freshwater and seawater splitting, as well as solar-to-hydrogen integrated system. This work could provide beneficial enlightenment for the establishment of advanced electrocatalysts with epitaxial heterointerfaces.

Automated summary

The rational design of epitaxial heterostructures based on the growth of compatible phases with lattice similarity can enhance electrocatalytic activity. The charge transfer and reinforced electron conduction at the epitaxial heterointerface between Ru clusters and Ni3N substrate are studied through theoretical simulations, leading to optimized adsorption behaviors and reduced activation energy barriers. The defect-rich nanosheets with the epitaxially grown cRu-Ni3N heterointerface show remarkable bifunctional catalytic activity in electrocatalytic OER and HER, as well as in alkaline freshwater and seawater splitting.