Sonochemical Synthesis and Characterization of UV-Driven Pt/ZnO Nanocomposites Used for Dye Degradation under UV Radiation

Abstract

Heterostructure Pt/ZnO nanocomposites were prepared by sonochemical-deposition method following the preparation of ZnO microflowers by simple precipitation method. Phase, morphology, oxidation state of element, specific surface area and optical properties of ZnO and heterostructure Pt/ZnO nanocomposites were characterized by X-ray powder diffraction, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Brunauer–Emmett–Teller (BET) surface area analysis, Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and UV-visible diffuse reflectance spectroscopy (DRS). The analytical results certified that face centered cubic metallic Pt⁰ nanoparticles were fully supported on the surface of nanopetals of hexagonal ZnO microflowers. In addition, the samples were studied for photodegradation of methylene blue (MB) and methyl orange (MO) under UV light irradiation. The heterostructure 0.5% Pt/ZnO nanocomposites have the highest MB and MO degradation because the Schottky barrier of metal–semiconductor interface played the role in preventing charge carrier recombination. The photocatalytic stability and trapping test of active radical for MB and MO degradation over heterostructure 0.5% Pt/ZnO nanocomposites were evaluated and discussed according to the experimental results.