Photocatalytic and antimicrobial activities of pure and Mn doped ZnO nanoparticles synthesised by Annona Muricata leaf extract

The present work aim to investigate the photocatalytic, antibacterial and antifungal activities of Zn1-xMnxO (x = 0.0, 0.03, 0.05 and 0.07) nanoparticles synthesised using the leaf extract of Annona Muricata via green synthesis method. The effect of Mn doping in the obtained nanopowder were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HRTEM), selected area diffraction pattern (SAED), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and UV-visible spectroscopy techniques. XRD pattern confirms hexagonal wurtzite structure of ZnO nanoparticles. Incorporation of Mn into the ZnO host lattice was confirmed by XPS measurement. Morphology of nanoparticles shows irregular, spherical shapes with agglomeration. Presence of Zn, Mn and O elements in the EDAX reveals the perfect nature of nanostructures. The synthesised pure and Mn-doped ZnO nanoparticles were found to be significant antibacterial activity against gram positive Bacillus subtilis, Staphylococcus aureus and gram negative Pseudomonas aeruginosa bacterial pathogens as well as the fungal strain of Candida albicans and Aspergillus Niger. The minimum zone of inhibition observed for bacterial and fungal pathogens confirms better antimicrobial activity of ZnO nanoparticles. The Mn-doped nanoparticle shows comparatively enhanced removal of methylene blue (MB), malachite green (MG) and Congo red (CR) dye under sunlight. These results indicates the green synthesised pure and Mn-doped ZnO nanoparticles have valuable applications in environmental and biomedical fields.