Supercapacitor Electrodes Obtained by Directly Bonding 2D MoS 2 on Reduced Graphene Oxide

Preparation-of-MoS-2-RGO — Preparation of MoS 2/RGO with three concentrations of MoS 2 on reduced graphene oxide, highlighting a schematic cross sectional view of the interaction between MoS 2/MoS2 layers and between MoS 2 layers/RGO.

Writers: Edney Geraldo da Silveira Firmiano, Adriano C. Rabelo, Cleocir J. Dalmaschio,Antonio N. Pinheiro, Ernesto C. Pereira, Wido H. Schreiner, Edson Robeto Leite

Keywords: Supercapacitor; reduced graphene oxide

Abstract: Layered molybdenum disulfide (MoS₂) is deposited by microwave heating on a reduced graphene oxide (RGO). Three concentrations of MoS₂ are loaded on RGO, and the structure and morphology are characterized. The first layers of MoS₂ are detected as being directly bonded with the oxygen of the RGO by covalent chemical bonds (Mo-O-C). Electrochemical characterizations indicate that this electroactive material can be cycled reversibly between 0.25 and 0.8 V in 1 m HClO₄ solution for hybrids with low concentrations of MoS₂ layers (LCMoS₂/RGO) and between 0.25 and 0.65 V for medium (MCMoS₂/RGO) and high concentrations (HCMoS₂/RGO) of MoS₂layers on graphene. The specific capacitance measured values at 10 mV s⁻¹ are 128, 265, and 148 Fg⁻¹ for the MoS₂/RGO with low, medium, and high concentrations of MoS₂, respectively, and the calculated energy density is 63 W h kg⁻¹ for the LCMoS₂/RGO hybrid. This supercapacitor electrode also exhibits superior cyclic stability with 92% of the specific capacitance retained after 1000 cycles.