Composites Photocatalysts for Sustainable Solar Energy Conversion

Antimicrobial resistance poses a significant threat to global health, amplified by factors such as water scarcity and suboptimal hygienic practices. Addressing AMR effectively necessitates a comprehensive strategy encompassing enhanced access to potable water, developing innovative antibiotics, and exploring alternative treatment modalities, such as harnessing solar photocatalysis with zinc oxide nanoparticles for water purification and antimicrobial applications. The Laser-Assisted Chemical Bath Synthesis (LACBS) technique facilitates the fabrication of pure ZnO nanostructures, providing a potentially efficacious solution for mitigating pathogen proliferation and managing wastewater. The photocatalytic degradation of MB and MO dyes was investigated using blue laser light at 445 nm, and degradation rates were determined accordingly. Ag-doped ZnO nanostructures were characterized through X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier-transform infrared spectroscopy. The antimicrobial efficacy of LACBS-synthesized ZnO nanoparticles was assessed against C. albicans, S. aureus, B. subtilis, E. coli, and K. pneumoniae using the disc diffusion method, revealing 40 mm, 37 mm, 21 mm, 27 mm, and 45 mm inhibition zones at the highest concentration of doped-Ag (4.5%), respectively. These inhibition zones were measured in accordance with the guidelines established by the Clinical and Laboratory Standards Institute. X-ray diffraction patterns for ZnO, ZnOAg_(1.5%), ZnO:Ag_(3%), and ZnO:Ag_(4.5%) samples revealed variations in intensity and crystallinity. Scanning electron microscopy exposed morphological disparities among the nanostructures, while energy-dispersive X-ray spectroscopy verified their elemental compositions. UV-Vis absorption analyses inspected the optical band gaps, and Fourier-transform infrared spectra identified the stretching mode of metal-oxygen bonds. Under blue laser irradiation, Ag-doped ZnO exhibited enhanced photocatalytic activity during the photocatalytic degradation. These nanoparticles, synthesized via the cost-effective and straightforward LACBS method, benefit from silver doping that augments their electron-trapping properties and photocatalytic activity, thereby enabling efficient dye degradation. Consequently, Ag-doped ZnO nanoparticles hold promise as a potent solution for counteracting drug-resistant microorganisms and as an effective disinfectant. Full article