Unlocking the photocatalytic and antibacterial properties of triple and quadruple doped ZnO nanoparticles (Mg/Cu/N-ZnO and Mg/Cu/N/B-ZnO) prepared by one pot facile solid state synthesis

Abstract

Due to their unique properties and suitability for a wide range of applications, nanometer-scale semiconductors such as ZnO have garnered much attention. We successfully synthesized undoped and doped ZnO (Mg/Cu/N-ZnO and Mg/Cu/N/B-ZnO) using the solid-state method and analyzed using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Raman Spectroscopy, UV − Visible Diffuse Reflectance (UV– Vis DRS), and Photoluminescence spectra (PL). The synthesized material exhibited a hexagonal structure in the presence of additional potentially doped ZnO defects, as evidenced by the XRD and Raman spectra. The scanning electron microscopy (SEM) study showed that the undoped ZnO exhibited a rod-shaped morphology with a non-uniform size distribution. In contrast, the doped ZnO particles had an almost spherical shape. The particle sizes of undoped ZnO are 91.52 nm, while doped ZnO particles are 74.92 nm for Mg/Cu/N-ZnO and 42.28 nm for Mg/Cu/N/B-ZnO. According to BET analysis, Mg/Cu/N- ZnO exhibits the highest specific surface area, measured at 803.009 m²/g. X-ray photoelectron spectroscopy verified the presence of dopants within the ZnO lattice. The UV-DRS study results showed that doping impacts the bandgap energy. The PL spectrum shows the formation of UV emission (∼400 nm) and visible emission (513–520 nm and ∼ 649 nm) peaks, indicating the inhibition of electron-hole recombination and various types of defects, including intrinsic and extrinsic defects. The photocatalytic activities of undoped ZnO and doped ZnO for methyl violet (MV) degradation were investigated using UV–vis spectroscopy after 120 min of exposure to visible light. Triple and quadruple-doped ZnO showed excellent photocatalytic ability to degrade a 93 – 95 % solution of methyl violet. The material’s stability was assessed through five cycles of the photocatalyst, and characterization data (XRD, XPS) for the catalyst utilized are also provided. Antibacterial activity increased against S. aureus and E. coli bacteria in quadruple-doped ZnO samples. The Mg/Cu/N/B-ZnO sample had the most significant antibacterial activity, with an average zone of inhibition measuring 9.85 mm for S. aureus and 11.95 mm for E. coli.