ABSTRACT The extensive use of pesticides in modern agriculture has led to serious environmental contamination and health concerns. In this study, a green synthesis route was employed to fabricate ZnO/CuS nanocomposites (NCs) for the photocatalytic degradation of chlorpyrifos pesticide in aqueous media. The NCs were synthesized using banana peel extract and rice starch water as eco‐friendly reducing and stabilizing agents. Four samples with different ZnO: CuS ratios (1:1, 1:2, 1:3, and 1:4) were prepared via a precipitation method. The structural, optical, and morphological properties of the synthesized NCs were characterized using XRD, FTIR, UV–vis spectroscopy, and FESEM analysis. XRD results confirmed the hexagonal phases of ZnO and CuS, with crystallite sizes of 25.04, 8.9, 10.5, and 23.14 nm for samples A , B , C , and D , respectively. Optical studies revealed reduced bandgap energies ranging from 2.2 to 2.0 eV, indicating improved visible‐light absorption due to the formation of the ZnO/CuS heterostructure. The photocatalytic activity of the synthesized NCs was evaluated through the degradation of chlorpyrifos under UV–vis light irradiation. Among the prepared samples, sample B (ZnO: CuS = 1:2) exhibited the highest photocatalytic performance, achieving 93.65% degradation within 120 min using 20 mg of catalyst at room temperature (28.5°C) for an initial pesticide concentration of 1 mmol in 0.5 L solution. The enhanced photocatalytic activity is attributed to efficient charge transfer between ZnO and CuS, which suppresses electron–hole recombination and promotes the formation of reactive oxygen species (ROS). These findings demonstrate that green‐synthesized ZnO/ CuS NCs are promising and cost‐effective photocatalysts for the removal of pesticide contaminants from wastewater.
Mishra et al. (Wed,) studied this question.