Preparation and band gap shift of nano-structured metal oxides and their activity in disinfection of water using laser induced photo-catalysis

Nano structured metal oxides (WO₃ and ZnO) were synthesized and impregnated with a noble metal palladium and it was found from the absorption spectra that the band gap energies of the palladium doped material revealed blue shifts compared to the band gap energies of their pure counterparts. Pure and doped material synthesized were used as a photo-catalyst in the presence of 355 nm UV laser radiation in the process of deactivation of Escherichia coli micro organism in water and it is observed that the doped material show a considerable enhancement of the deactivation process with higher bacteria decay rate constant and shorter depletion time, which is related to the widened band gap due to palladium doping.