Proficient Engineering of NiO/Cu2S/rGO heterojunction photocatalysts: fabrication, dye degradation, and mechanism pathways towards environmental remediation

Contemporary fashion industry uses numerous dyes and global attention has been drawn to the widespread use, toxicity, carcinogenicity, and bioaccumulation of mixed dyes. Therefore, researchers and scientists are focused on using broad spectrum of photocatalysts to achieve dye remediation with maximum efficiency. Herein, we report the fabrication of novel NiO/Cu₂S/rGO ternary nanocomposites synthesized via the one-step hydrothermal method. The as-synthesized sample was analyzed by applying different analytical techniques, such as XRD, FTIR, UV-DRS, SEM, EDX, elemental mapping, and HRTEM analyses. The results confirmed that the NiO and Cu₂S nanoparticles are decorated on the 2D-rGO nanosheets. An interfacial ternary heterostructure was successfully utilized for the photocatalytic environmental remediation of mixed dye pollutants under UV-light irradiation. Several key factors contribute to the remarkable photocatalytic performance of these heterostructures, including the wide spectrum of the harvested light, good charge separation, and rapid charge transport. The optimized NiO/Cu₂S/rGO ternary nanocomposites exhibited the highest degradation efficiency of 92.4%, 97.9% and 91.6% for RhB, MB and mixed (RhB and MB) dyes, respectively. In contrast, the tentative photocatalytic mechanism pathway, scavengers experiments, recyclability and stability were also investigated. The results reveal that (*O₂⁻) and *OH radical species play a major role under UV-light irradiation. The NiO/Cu₂S/rGO ternary nanocomposites have potential for the effective degradation of organic dyes in industrial wastewater and environmental remediation.