Removal of hexavalent chromium from water using a heterojunction system of CuO/BiOCl photocatalyst

This research explores the photocatalytic reduction of hexavalent chromium (Cr(VI)) through a heterojunction system comprising BiOCl and CuO. The CuO/BiOCl nanocomposites, at different percentage compositions CuO/BiOCl(5%), CuO/BiOCl(10%), CuO/BiOCl(20%), CuO/BiOCl(30%), and CuO/BiOCl(50%), were synthesized using a facile and eco-friendly hydrothermal process. The formation of a heterojunction system was confirmed by X-ray diffraction (XRD), microscopy techniques, and UV-vis spectroscopy. At the same time, the morphological and optical characteristics of CuO/BiOCl nanocomposite were investigated using SEM/TEM techniques and absorption spectroscopy. The performance of CuO/BiOCl nanocomposites as photocatalysts in the degradation of Cr(VI) under visible light irradiation was investigated. Factors such as the effects of solution pH, catalyst dosage, and initial Cr(VI) concentration were assessed. The nanocomposites showed significant photocatalytic performance, with CuO/BiOCl(5%) composite achieving 97.91% of Cr(VI) reduction efficiency in 90 min under visible light. The synergistic interaction between the two semiconductor photocatalysts improved charge separation and light absorption, indicating their potential for wastewater treatment.