Bayberry-like Pt nanoparticle decorated ZnO nanorods for the photocatalytic application

Abstract

The preparation of the nanocomposites zinc oxide/platinum (ZnO/Pt) has attracted much attention with regard to improving the photocatalytic efficiency of ZnO, but most studies have focused on the use of ZnO/Pt in conventional powdered spherical nanocrystals only. In this experiment, bayberry-like Pt nanoparticles (NPs) were successfully synthesized and deposited on the surfaces of ZnO nanorods (NRs) that were hydrothermally grown on glass substrates. The bayberry-like Pt NPs, which had a diameter range of 40–70 nm and consisted of many nanodots with a diameter < 5 nm, were spread uniformly on the surface of the ZnO NRs via the drop-casting method. The presence of the Pt NPs increased the photocatalytic activity of ZnO NRs for methylene blue (MB) degradation by 54% and 32% under UV and visible light irradiation, respectively. This improvement can be attributed to the presence of Pt, which acted as an electron trap and can inhibit the rate of electron–hole recombination. It may also be credited to the morphology of the bayberry-like Pt NPs, which consisted of many nanodots that can trap light in the surroundings of the nanodots, thereby enhancing the light scattering and absorption and enlarging the surface area for oxygen and hydroxyl ion adsorption. Keywords: Pt, ZnO, Bayberry-like, Nanoparticles, Nanorods, Photocatalytic