Physicochemical and electrochemical investigation of lead sulphide-graphene oxide hybrid nanostructure for energy storage applications

The emerging trend of advanced electrodes with greater specific capacitance (C_s) and favourable cycle life is acquiring significant attention of transition metal sulphide composites for energy storage devices. Therefore, this study demonstrates the effective creation of lead sulphide-graphene oxide (PbS/GO) nanohybrid using a simple hydrothermal method, which restricts agglomeration and enhances the electrochemical properties of the developed electrodes. The scanning electron microscopy (SEM) examination verified the distribution of PbS flakes on GO sheets, improving the performance. The nanohybrid employed as an electrode in supercapacitors demonstrated a C_s of 1371.57 F/g at a current density (j) of 1 A/g in a 2.0 M KOH using a three-electrode setup. Remarkably, it retained an exceptional specific capacitance of 94.12 % over 4,000 cycles. Furthermore, the asymmetric configuration (PbS/GO//AC) achieves a more excellent C_s of 251 F/g at 1 A/g and an impressive energy density of 17 Wh/kg when operated at a power density of 252 W/kg. The outstanding electrochemical performance results from the extensive surface area (121.61 m²/g) and mesoporous nature of the hybrid electrode, which provides additional passages and electroactive sites for electrolyte interaction during the oxidation–reduction phenomenon. Additionally, the uniform decoration of PbS nanoflakes on conductive GO nanosheets decreases the agglomeration and contributes to the pseudocapacitive behaviour. Therefore, the exceptional performance of the PbS/GO hybrid electrode holds considerable promise for the advanced supercapacitors used in portable and wearable electronics.