Layer-by-layer self-assembled GO-MoS2-Co3O4 three-dimensional conducting network for high-performance supercapacitors

Three-dimensional materials facilitate the development of electrode materials used in supercapacitors with their unique structures and outstanding electrical properties. In this study, Three-dimensional GO-MoS2-Co3O4 composites based on MoS2 and graphene oxide (GO) were prepared by hydrothermal and electrostatic adsorption methods and were used to study supercapacitor performance. The differently charged MoS2 and GO nanosheets were self-assembled layer-by-layer via electrostatic interactions. Subsequently, a composite containing Co3O4 particles highly dispersed in GO/MoS2 matrix was prepared by in-situ reduction with metal salts in the absence of a reducing agent. The GO-MoS2-Co3O4 showed an excellent specific capacitance of 277 F g(-1) at 1 A g(-1). The assembled asymmetric supercapacitor of GO-MoS2-Co3O4//GC, with graphitic carbon (GC) as the negative electrode and GO-MoS2-Co3O4 as the positive electrode, exhibited an electrochemical window of 1.65 V. It also exhibited excellent specific capacitance (135.3 F g(-1) at 1 A g(-1)), great cycling stability (retaining 87% after 3000 cycles at 1 A g(-1)), and high specific energy (51 Wh kg(-1) at 825 W kg(-1)).