A New Sunlight Active Photocatalyst Based on CuO-TiO 2 -Clay Composite for Wastewater Remediation: Mechanistic Insights and Degradation Optimization

In this wok, a new CuO-TiO2-clay composite was synthesized by the sol–gel method and explored as a photocatalyst for wastewater remediation. The synthesized material was characterized by X-ray diffraction (XRD), Raman spectroscopy (RS), diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), X-ray fluorescence (XRF), and Fourier Transformer InfraRed (FTIR). The photocatalytic activity of the composite was tested on tartrazine dye (TARTZ) removal. Particular emphasis was focused on the effect of the key operating parameters such as photocatalyst dose, pH, light intensity, and initial concentration of dye. The optimization of three simultaneous parameters, namely methylene blue concentration (MB; pollutant in competition with TARTZ), NaCl concentration, and irradiation time, was examined via the response surface methodology (RSM). The CuO-TiO 2 -clay composite showed the best photocatalytic performance with 62.50