Solid state engineering of Bi2S3/rGO nanostrips: an excellent electrode material for energy storage applications

Abstract

The study presents a novel, one-pot, and scalable solid-state reaction scheme to prepare bismuth sulphide (Bi₂S₃)-reduced graphene oxide (rGO) nanocomposites using bismuth oxide (Bi₂O₃), thiourea (TU), and graphene oxide (GO) as starting materials for energy storage applications. The impact of GO loading concentration on the electrochemical performance of the nanocomposites was investigated. The reaction follows a diffusion substitution pathway, gradually transforming Bi₂O₃ powder into Bi₂S₃ nanostrips, concurrently converting GO into rGO. Enhanced specific capacitances were observed across all nanocomposite samples, with the Bi₂S₃@0.2rGO exhibiting the highest specific capacitance of 705 F g⁻¹ at a current density of 1 A g⁻¹ and maintaining a capacitance retention of 82% after 1000 cycles. The superior specific capacitance is attributed to the excellent homogeneity and synergistic relation between rGO and Bi₂S₃ nanostrips. This methodology holds promise for extending the synthesis of other chalcogenides-rGO nanocomposites.