Coprecipitation synthesis of transition metal (Al, Mn, Cu, Ag) doped zinc oxide nanopowders: characterization, photocatalytic test, and comparison study

The study successfully produced ZnO and ZnO nanoparticles doped with transition metals (TMZO-NPs) using the co-precipitation method. Various properties of these nanoparticles were examined, including their structure, morphology, electronic behavior, optical characteristics, vibrations, and photocatalytic abilities. The analysis confirmed that all nanoparticles possessed a hexagonal wurtzite crystalline structure, with particle size being influenced by the presence of transition metals (Al, Ag, Cu, Mn). The particles exhibited a preference for orientation along the (002) axis. The shift in peak positions towards higher angles suggested that the TM might replace Zn ions in the ZnO lattice. The surface structure of the nanoparticles displayed a combination of spherical and hexagonal shapes. Further analysis identified important bands related to the stretching modes of TM-O and Zn-O bonds. The absorption properties and edges were also affected by the presence of TM. In the degradation study, both pure ZnO and TMZO-NPs were tested for their ability to break down methylene blue (MB) under UV light exposure for 90 min. Among the nanoparticles, Al-doped ZnO (AlZO-NPs) demonstrated the highest degradation efficiency, achieving 97.14% removal of MB within the given exposure time. The photocatalytic process followed a pseudo-first-order kinetics, indicating a strong correlation. This suggests that AlZO-NPs hold promise as a material for use in photocatalytic applications.