Hydrothermally synthesized transition metal doped ZnO nanorods for dye degradation and antibacterial activity

In this study, Ni-doped ZnO (NZ) and Ni–Mn dual-doped ZnO (NMZ) NPs were synthesized by hydrothermal method. Various analytical techniques, such as XRD, UV–vis, FTIR, PL, SEM, EDAX, and HR-TEM, were employed to investigate the effect of doping transition metal ions in the ZnO lattice. The powder X-ray diffraction (XRD) patterns confirmed a hexagonal structure with average crystallite sizes of 30.66 nm and 27.09 nm for NZ and NMZ nanoparticles, respectively. Tauc’s plot showed that the energy bandgap was redshifted to 2.9 from 2.8 eV by doping transition metal ions in ZnO. The photoluminescence spectrum displayed various peaks, indicating the emission behaviour of the nanomaterials. The photocatalytic performance of the catalysts was tested under visible light sources against Crystal Violet (CV) dye. The degradation efficiency, for NMZ achieved a maximum degradation efficiency of 91.1 %. Antibacterial activity was evaluated against gram-positive (B. subtilis and S. aureus) and gram-negative (E. coli and P. aeruginosa) bacteria. The NMZ exhibited higher photocatalytic and antibacterial activity than NZ.