Simple preparation of scale-like CuO nanoparticles coated on tetrapod-like ZnO whisker photocatalysts

Scale-like copper oxide (CuO)/tetrapod-like ZnO whisker (T-ZnOw) nanocomposites were fabricated using poly(ethylene glycol) (PEG; M-w = 400) as a soft template by a simple and environmentally friendly method without the use of hydroxide reagents at low temperatures. The structures and morphologies of the samples were investigated in detail, and the photocatalytic properties of the samples were determined using photoluminescence (PL) detection and the photocatalytic degradation of cationic pollutant (methylene blue, MB) and anionic pollutant (methyl orange, MO) aqueous solutions under ultraviolet (UV) irradiation. Large numbers of scale-like CuO nanoparticles were deposited on the T-ZnOw surfaces in an ordered fashion; the amount of scale-like CuO nanoparticles increased, and the arrangement became more ordered with increasing PEG 400 content. The PL emission peak intensities of the samples changed with increasing PEG 400 content. All the CuO/T-ZnOw nanocomposites showed excellent photocatalytic activities in the degradation of MB and MO aqueous solutions under UV irradiation when the PEG 400 concentration was less than or equal to 0.60 mol/L. The photocatalytic properties of the samples improved with increasing PEG400 concentration, but deteriorated when the PEG 400 concentration was increased further; this was reflected by the emission peak intensities in the PL spectra. The nanocomposites showed better efficiency for MB degradation than for MO degradation under the same conditions. (C) 2014, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.