Chemical Engineering Journal, Vol.307, 966-980, 2017
Effect of morphology of zinc oxide in ZnO-CdS-Ag ternary nanocomposite towards photocatalytic inactivation of E. coli under UV and visible light
A novel ternary hybrid, ZnO-CdS-Ag was synthesized and photocatalytic inactivation of E. coli using UV and visible light irradiation was performed. The morphology of synthesized materials was validated by SEM, whereas the crystal details were evaluated by XRD and TEM. Diffuse reflectance was measured to determine the band gap and analyse the absorption range of light by synthesized composites. The effect of morphology was examined by comparing the photocatalytic activity of nanorods with combustion synthesized ZnO nanoparticles. High aspect ratio, the presence of maximum number of charge carriers at the surface, dimensional anisotropy, ease in charge transfer through uni-direction of nanorods resulted in decreased recombination and high charge separation. This was found to be the reason of augmented photoactivity of nanorods over combustion synthesized nanoparticles. Absorption of light was increased by decorating CdS as a photosensitizer on ZnO surface. Enhanced photocatalysis was achieved by impregnation of 1% Ag on the surface of ZnO-CdS. First order kinetics was observed for all the reactions. The rate constant for inactivation reaction in presence of ZnO (NR)-CdS-Ag was 11 +/- 0.3 and 12 +/- 0.6 h(-1) in UV and visible light, respectively. (C) 2016 Elsevier B.V. All rights reserved.