Crucial roles of interfacial coupling and oxygen defect in multifunctional 2D inorganic nanosheets

Abstract

An effective way to optimize the functionality of inorganic 2D nanosheets can be developed by tailoring their interfacial electronic coupling and crystal defect in the hybrid structure. The heterolayer hybridization between exfoliated Co-Fe-layered double hydroxide (LDH) and RuO2 nanosheets can provide an efficient way of optimizing the interfacial coupling and oxygen vacancy of restacked nanosheets. The obtained Co-Fe-LDH-RuO2 nanohybrid shows outstanding electrode performance for Li-O-2 batteries with excellent bifunctional oxygen electrocatalytic activity, which is much superior to those of the precursor materials. In-situ X-ray absorption spectroscopic and electrochemical characterizations highlight the remarkable improvement of electrocatalysis kinetics and electrochemical stability upon hybridization, which is attributable to the intimate interfacial interaction and oxygen vacancy formation of restacked 2D inorganic nanosheets. This study underscores that a fine-control of electronic coupling and defect structure via heterolayer hybridization is quite effective in exploring high-performance bifunctional electrocatalysts applicable as Li-O-2 cathode.