Ag-Doped ZnO–CuO Nanocomposites: Coprecipitation Synthesis and Evaluation of Photocatalytic and Antioxidant Activities

Ag-doped ZnO–CuO nanocomposites were successfully prepared by a simple coprecipitation technique and studied for photocatalytic and antioxidant properties. The structural and morphological properties of the synthesized ZnO–CuO nanocomposites were studied by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), and Energy-dispersive X-ray analysis (EDAX). The XRD studies confirmed the formation of crystalline ZnO, CuO, and Ag, while the SEM studies revealed a heterogeneous and aggregated nanostructure on a nanoscale. The photocatalytic activity of Ag-doped ZnO–CuO nanocomposites was also studied by decomposing methylene blue dye under light irradiation, showing enhanced activity compared to undoped particles. The improved activity is due to a combined effect of Ag doping and a ZnO/CuO heterojunction, which helps to separate charges and decrease electron-hole recombination. In addition, antioxidant activities were also investigated using a free radical scavenging method, and it was found that Ag-doped ZnO/CuO nanocomposites exhibited strong antioxidant activity that was concentration-dependent. Based on this observation, it could be determined that Ag-doped ZnO/CuO nanocomposites produced through the coprecipitation method possess strong photocatalytic and antioxidant properties, which could be employed in future environmental applications and could be used as a medicine to cure diseases involving cellular oxidation.