Photo-catalytic degradation of methyl violet dye using zinc oxide nano particles prepared by a novel precipitation method and its anti-bacterial activities

• Nano ZnO particles were obtained by employing novel precipitation method.
• Structural features, surface morphology, optical characteristics, etc., were evaluated using XRD, FTIR, SEM, PL, UV–vis, etc.
• Photo-catalytic property of as obtained ZnO was studied against the degradation of methyl violet dye.
• ZnO NPs also exhibit better anti-antimicrobial activities against three bacterial strains.
• A statistical t-test was performed with MATLAB to confirm the influence of ZnO NPs over the bacterial strains.

Synthesis of different shaped nano-particles using novel methodologies always attracts great importance in research. This report details with the preparation of zinc oxide nano particles (ZnO NPs) using a very simple, efficient precipitation method. ZnO NPs were obtained by the calcination of zinc oxalate powder precipitated from a reaction mixture containing zinc acetate and ammonium oxalate. As obtained ZnO NPs were characterized using field emission scanning electron microscopy (FESEM), X-Ray Diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), photo-luminescence spectroscopy, etc. The photo-catalytic property of ZnO NP was studied using UV–vis spectroscopy for the degradation of methyl violet (MV) by exposing to sunlight. Complete degradation of methyl violet was noticed on exposing the suspension containing sonicated ZnO NPs in an aqueous medium with MV in 60–80 min. Antibacterial studies of ZnO NPs were performed against bacterial strains such as Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus. ZnO NPs exhibit high inhibition towards P. aeruginosa and E. coli; however it shows minimum inhibition towards S. aureus. A difference of 0.461 a.u was observed in the mean of optical densities between P. aeruginosa and S. aureus. Statistical t-test was performed to find the significance of this difference and the results confirmed that this difference was due to the influence of the prepared ZnO NPs on the bacterial strains.