Zinc/lead bimetallic sulfides as hybrid material for high-performance aqueous asymmetric supercapacitor and photocatalytic degradation of organic dye

Wastewater pollution and sustainable energy resources are the utmost crises of the present world. To address these issues, photocatalysis and supercapacitors are sustainable and effective technologies. Over the years, the spontaneous evolution of bimetallic materials has demonstrated excellent performance through their unique architecture, metallic complexes, and porosity. Towards these goals, metal sulfides offer tremendous properties due to their high conductivity, and high charge storage capability. These studies introduce a novel bimetallic sulfide material (Zinc Sulfide/lead Sulfide) (ZnS/PbS) with a unique architecture derived from pristine zinc sulfide and lead sulfide. The Figure of merits for supercapacitors like specific capacity, high electronic conductivity, and highly redox active for ZnS/PbS (30:70) is achieved due to high surface area and unique 2D-sheet like morphology as compared with the pristine zinc and lead sulfide. The highest specific capacity achieved by ZnS/PbS (30:70) is 1083 C/g at 5 mV/s. The specific capacity may be attributed to the highly mesoporous nature of the material with well-defined 2D-sheet-like morphology. The hybrid device depicts a remarkable energy density (18 Wh/kg) and power density (7200 W/kg) with 90.42 % capacitive retention and 81.77 % coulombic efficiency after 5000 cycles. The high retention rate is due to the non-destructive 2D-sheet-like morphology which is sustained even after 5000 cycles. Additionally, the assembled hybrid coin cell can power the commercially available calculator for 86 minutes which shows its potential for real-world application. The photodegradation studies show that ZnS/PbS (30:70) decolor the methyl orange dye solution in 270 mins at pH 10 with good stability for 5 consecutive cycles. The mentioned studies indicate ZnS/PbS (30:70) is a potentially viable candidate as electrode material in asymmetric supercapacitors and environmental remediation.