In situ electrochemical synthesis of polypyrrole CuO MoO nanocomposite on graphene oxide nanosheets for hydrogen generation and supercapacitors.

In this work, a simple, single-step electrochemical method is used to decorate a ternary Polypyrrole-CuO-MoO (PPy-CuO-MoO) nanocomposite on Graphene Oxide (GO) nanosheets formed on a Graphite Foil Electrode (GFE). The characterization confirmed successful synthesis of ternary nanocomposite, and electrochemical tests showed the electrode performed well as both a supercapacitor and a hydrogen evolution reaction (HER). The investigation of the hydrogen production reaction by the PPy-CuO-MoO/GO/GFE shows that this electrode has a smaller Tafel slope and overpotential. Additionally, the PPy-CuO-MoO/GO/GFE has a specific capacitance of 1010.30 mF cm at 1 mA cm in a 0.5 M HSO electrolyte solution. The evaluation of the fabrication of a symmetric solid-state supercapacitor device shows that the constructed device has an excellent capacitance of 596.5 mF cm at 1 mA cm and a cyclic stability of 82.4% after 6000 GCD cycles. For hydrogen evolution reaction, the electrode demonstrated an overpotential of 361 mV at 10 mA cm and a Tafel slope of 142 mV dec, indicating favorable electrocatalytic activity. These results highlight the potential of the synthesized nanocomposite as a multifunctional electrode material for both energy storage and clean energy production.