Synergistic adsorption-photocatalysis effect of CuO/TiO2 composite for high-efficient degradation of methyl orange

The issue of organic dye pollutant in wastewater system is a major of global concern for human health. This work reports the synthesis of CuO/TiO₂ nanocomposites and its visible light-driven photocatalytic degradation of Organic dyes. CuO/TiO₂ nanocomposites was produced by process that involves chemical precipitation and thermal treatment method, and characterized for its structural property using X-ray diffraction (XRD), SEM, EDS, and functional groups using Fourier transfer infrared (FTIR) spectroscopy, and applied its application in light-driven photocatalytic degradation of methyl orange (MO), ideal organic dye. The influence of such parameters as adsorbent dosage, dye initial concentration, solution pH, and contact time on the uptake of the dye was also investigated, and over 92.7% of the dye has been removed using 50 mg of adsorbent for 10 mg/L of dye concentration at the optimum pH 6 and RT for a shaking time of 60 min. The adsorption data could be best described by pseudo-second-order model with a correlation coefficient (R²) of 0.9969 undertaken for a shaking time of 3 h, where the adsorption attains equilibrium. The adsorption experiments of the CuO/TiO₂ followed the pseudo-second-order kinetic model, and the adsorption isotherms were accurately represented by the Langmuir model. The degradation of methyl orange (MO) by CuO/TiO₂ fitted well with the Langmuir-Hinshelwood model, and MO removal was obtained through a synergistic effect of adsorption and photocatalysis. Unlike previous reports that focused mainly on either absorption or photocatalysis, our work demonstrating the synergistic effect of adsorption and photocatalysis in TiO2/CuO composite synthesized via simple precipitation-thermal method. Therefore, the synthesized composites may potentially be used for the removal of organic water pollutants from water.