Photo-degradation of organic dye by zinc oxide nanosystems with special defect structure: Effect of the morphology and annealing temperature

The fabrication of strong photocatalysts applied to the degradation of organic pollutants is necessary in environmental applications. In a single-stage method, acetate precursor and poly vinyl pyrolydine are used to produce ZnO nanostructures with various morphologies in annealing temperatures ranging from 300 to 900 degrees C. The physical properties of the prepared nanostructures were characterized by SEM, TEM, XRD, BET, DRS, CHN analysis and PL spectroscopy. The SEM images exhibit a variety of the asprepared hexagonal zinc oxides including wires, rods, particles and porous network of welded particles of ZnO nanoparticles. The results of the photocatalytic degradation of methylene blue as an organic dye in aqueous suspension showed that the morphology of ZnO nanostructures influences on the photocatalytic efficiency of ZnO nanostructures, greatly. For the best result, the highest MB degradation occurs by ZnO nanowires within 16 min and in others samples, degradation of higher than 95% occurs within 20 min. The XRD and PL spectroscopy revealed neither V-zn nor O-1, are in all of samples but only Vo(-), Vo(2-) and Zn, exist in ZnO nanostructures. (C) 2013 Elsevier B.V. All rights reserved.