LAUSR

Abstract In this study, different morphologies of zinc oxide (ZnO) powders were obtained via solution combustion route using poly(vinyl-pyrrolidone) (PVP) as fuel at various fuel to oxidant ratios. The increase of fuel amounts led to the transformation of giant pyramid-like particles to hexagonal nano-disk ones. N2 adsorption-desorption isotherms showed that the specific surface area increased from 23 to 41 m2/g at the higher fuel contents. By considering the decrease of particle size, the band gap energy value was turned from 3.02 to 3.13 eV. The ZnO powders prepared at a fuel to oxidant ratio of 1.5 photodegraded about 69 % of methylene blue during 3 h ultraviolet light irradiation. The high photocatalytic activity was attributed to the low recombination rate of electron-hole pairs and the high specific surface area.