Dual-function g-C3N4 anchored Cu–ZnS hybrid nanostructures for sustainable energy storage and environmental remediation

Abstract

The mounting global imperative for sustainable energy storage and effective wastewater treatment necessitates the innovation of multifunctional materials capable of addressing both challenges in tandem. In the present work, we demonstrate the fabrication of a hybrid nanostructure comprising graphitic carbon nitride (g-C₃N₄) integrated with Cu–ZnS, strategically engineered for dual functionality in photocatalytic and supercapacitor domains. X-ray diffraction (XRD) analysis confirmed the successful formation of the Cu–ZnS/g-C₃N₄ composite, revealing a synergistic coexistence of hexagonal and cubic ZnS crystal phases. Morphological characterization illustrated a uniformly integrated architecture, wherein Cu–ZnS nanoparticles were homogeneously distributed across the g-C₃N₄ nanosheets. BET surface area analysis indicated a pronounced enhancement, reaching 148.16 m² g⁻¹, representing a 1.6-fold increase relative to pristine Cu–ZnS. The multifunctionality of the composite was substantiated through its superior performance in both energy storage and environmental remediation. Specifically, the optimized CuZnS-GCN25 electrode exhibited an impressive specific capacitance of 275 F g⁻¹ at 1 A g⁻¹, retained 92.5% of its capacitance over 10 000 charge–discharge cycles, and maintained 70% retention at an elevated current density of 20 A g⁻¹ in a two-electrode configuration. In photocatalytic applications, CuZnS-GCN25 facilitated the efficient degradation of amoxicillin (AMX), achieving 92.4% removal under visible light within 60 minutes, consistent with pseudo-first-order kinetics (k = 0.029 min⁻¹). These results highlight the significant potential of CuZnS-GCN25 as a high-efficiency, dual-purpose material for sustainable water treatment and advanced hybrid energy storage systems.