High-yield preparation of molybdenum disulfide/polypyrrole hybrid nanomaterial with non-covalent interaction and its supercapacitor application

Molybdenum disulfide (MoS₂) incorporated with a conducting polymer can be a promising nanomaterial for use as low-cost electrodes in supercapacitors. MoS₂ nanosheets are generally prepared by the high-pressure hydrothermal method, which has a few drawbacks such as low exfoliation yield, safety issues, and long-time processing. Herein, we report a simple and effective method for the high-yield (~72.5%) preparation of a MoS₂/polypyrrole (MPY) hybrid nanomaterial via sonochemical exfoliation of ground bulk MoS₂ in a polar aprotic solvent and subsequent chemical oxidative polymerization of pyrrole (PY) onto the MoS₂ nanosheets. The strong non-covalent Mo–N bonding lowers the interfacial resistance, and the morphology of polypyrrole (PPY) can be easily controlled by varying the PY content. The MPY hybrid nanomaterial exhibited a maximum surface conductivity of 991 S sq., which is very high compared to that of pristine MoS₂ nanosheet (~3.6 × 10^–7 S sq.). When used in supercapacitors, the specific capacitance of the hybrid nanomaterial is 312 F g^–1. Thus, improved capacitance retention with increase in the scan rate and enhanced diffusion process during electrochemical reactions result in good supercapacitor performance, which is important for the mass production of energy-storage devices.