The photocatalytic as well as the antimicrobial activity of the synthesized ZnO nanoparticles (ZnO-NPs) through solution based approach have been presented in this study. ZnO-NPs have been characterised by thermogravimetry/differential thermal analysis (TG/DTA), ultraviolet-visible (UV–Vis), Fourier transform infrared (FTIR) and Raman spectroscopy. Raman studies confirm that it has stable wurtzite structure. FTIR spectrum confirms the Zn–O band at ~460 cm-1. Optical studies reveal that the optical band gap value increases with increasing annealing temperature. The photocatalytic activity of the ZnO-NPs has been evaluated for removal of pollutants from wastewater by measuring COD and BOD. Results show that ZnO-NPs are capable of working efficiently for waste water treatment. ZnO-NPs also demonstrate antimicrobial activity against gram-positive and gram-negative bacterial strains
