Actinomycetes-mediated Fabrication of ZnO–doped TiO₂ Nanoparticles: A Sustainable Approach for Antimicrobial and Photocatalytic Applications

The present study focuses on the synthesis, characterization and determining multifunctional properties of ZnO-doped TiO2 nanoparticles. UV–Vis spectroscopic analysis demonstrated a strong absorption peak confirming the role of ZnO doping in modulating the electronic configuration of TiO2. The FTIR spectra exhibited characteristic vibrational features which imply the presence of capping agent in secondary metabolites of actinomycetes, while XRD analysis confirmed the coexistence of anatase TiO2 and wurtzite ZnO phases. The SEM micrographs demonstrated predominantly spherical particles with slight agglomeration with an average size of 22 nm. Antimicrobial activity assays revealed remarkable zone of inhibition, with the most intense activity against Staphylococcus aureus, succeeded by Bacillus subtilis and Escherichia coli. Further, the photocatalytic efficiency of the nanoparticles was validated through methylene blue degradation studies. The ZnO-TiO2 nanoparticles exhibited substantial dye removal, attributable to enhanced electron-hole separation and extended visible light absorption. Collectively, the findings suggest that ZnO-doped TiO2 nanoparticles combine desirable optical, structural, antimicrobial, and photocatalytic properties, making them promising candidates for biomedical and environmental remediation applications.