Nano-NiO as a photocatalyst in antimicrobial activity of infected water using laser induced photo-catalysis

Nano NiO photo catalyst was synthesized by sol gel method and it is used as a photo catalyst in conjunction with 355 nm laser radiation in the process of disinfecting water infected with Escherichia coli microorganism. When synthesized nano-NiO material is used as a photo catalyst, a bacteria decay rate constant of 0.35 min-1 and this rate constant is higher than the bacteria decay rate constant of 0.24 minutes−1 for TiO2 as a photo catalyst under same catalytic concentration and laser pulse energy. From the TEM study, a grain size as low as 20–40 nm was observed and the absorption study showed a band gap of 3.85 eV. The dependence of depletion rate of bacterial count in the infected water on the nano-NiO concentration and the irradiating laser pulse energy were carried out.