Sunlight-enhanced catalytic degradation over Ag–CuO nanoparticles thin films prepared by DC/RF sputtering technique

Herein, we report sunlight-activated photo-catalysis response of direct current radio frequency (DC/RF)-sputtered Ag–CuO nanoparticles thin films. We have adopted this approach for facile removal and easy recovery of thin films after use. Ag was incorporated at 2.5 and 5.4 wt% with reference to pure CuO. Structural analysis through X-ray diffraction showed successful incorporation of Ag into the CuO lattice. Surface morphological observation was carried out using a field emission scanning electron microscope, which showed a uniform deposition of the subjected thin films. The surface composition and change in the chemical state of pure and incorporated thin films were studied by X-ray photoelectron spectroscopy. In addition to structural and surface analysis, optical band gap evolution was also studied through UV–visible spectroscopy. The obtained results reflected that optical band gap decreased from 1.84 to 1.77 and 1.61 eV for 0, 2.5 and 5.4 wt% Ag, respectively. Methylene blue dye was used to investigate the photo-catalytic degradation response of deposited thin films in sunlight. Furthermore, the effect of pH and dye concentration was also taken into account. The degradation results indicate the acceleration of degradation process with the Ag incorporation into CuO lattice. Moreover, the pH also contributes positively to the degradation progression. This research study could provide a platform to understand and develop metal oxide thin films with an efficient photo-catalytic response in sunlight.