Hierarchical Flower Structured Bi₂S₃/Reduced Graphene Oxide Nanocomposite for High Electrochemical Performance

A biomolecule assisted synthesis of bismuth sulfide (Bi₂S₃)/reduced graphene oxide (rGO) composite nanostructures by one-pot hydrothermal method. The structure, morphology and elemental analysis of the synthesized material were studied by X-ray diffractometer (XRD) and high resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy attest the reduction of graphene oxide and structural defects respectively. Absorbance and emission responses were studied by UV-vis-NIR and Photoluminescence spectroscopy. Electrochemical performances of the graphene oxide (GO), Bi₂S₃ and Bi₂S₃/rGO composite were investigated by Electrochemical workstation. The Bi₂S₃/rGO composite electrode attained five times higher specific capacitances of 817.6 F g⁻¹ at scan rate of 5 mV s⁻¹ and 680.6 F g⁻¹ at a current density of 1 A g⁻¹ compared to pure Bi₂S₃ (143.9 F g⁻¹ at 5 mV s⁻¹ and 152.23 F g⁻¹ at 1 A g⁻¹) respectively. Moreover, Bi₂S₃/rGO composite maintain better cyclic stability with the capacitance retention about 87% over 1000 cycles, and offer a high conductive connection for fast ion diffusion between electrode and electrolyte interface. The strong synergistic effect of the hierarchical flower structured/rGO composite suggest as a promising material for supercapacitor applications.