Preparation, characterization and photocatalytic activity of porous zinc oxide superstructure

A porous ZnO “timber-like” superstructures comprising nanoparticles was synthesized through the thermal decomposition of zinc oxalate precursor, prepared from zinc sulfate and oxalic acid, without additive(s) in water. The resulting ZnO superstructure was systematically characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and photoluminescence measurement. Using methyl orange as model, photocatalytic activity of ZnO superstructure was investigated. The heat treatment temperature and time was proved to have important influence for photocatalytic activity of ZnO superstructure. Longer heat treatment time at fixed heat treatment temperature and lower heat treatment temperature at fixed heat treatment time were favorable for the enhancement of photocatalytic activity. The optimum preparation condition for ZnO superstructure with higher photocatalytic activity was at 450 °C for 6 h.