In Situ Grown Heterostructure Based on MOF-Derived Carbon Containing n-Type Zn–In–S and Dry-Oxidative p-Type CuO as Pseudocapacitive Electrode Materials

The rational design of highly oriented and integrated heterostructures based on metal–organic framework (MOF)-derived carbon containing n-type metal chalcogenides (Zn–In–S/C) polyhedron and p-type metal oxide (CuO) nanowires was proposed. The p-type CuO nanowires were used as a stable scaffold to grow MOF-derived n-type Zn–In–S/C. The controlled and in situ fabricated Zn–In–S/C@CuO heterostructures provided a p–n heterojunction which enhanced the charge transfer, hence providing an improved overall electrochemical performance over its MOF and bare CuO counterpart. Coupled with density functional theory (DFT) calculations, the enhancement in the conductivity of the heterostructure was further verified. The symmetric supercapacitor device delivered an energy density of 7 Wh kg–1 at a power density of 4 kW kg–1. Overall, the theoretical and experimental investigation of the oriented in situ grown Zn–In–S/C@CuO heterojunction with better cycling stability and electrochemical activity could be a useful asset for energy storage devices.