Sonochemical Synthesis of Pd Nanoparticle/ZnO Flower Photocatalyst Used for Methylene Blue and Methyl Orange Degradation under UV Radiation
Prakasit Intaphong, Anukorn Phuruangrat, H. Yeebu, Kamran Akhbari, Thawatchai Sakhon, Somchai Thongtem, Titipun Thongtem
Abstract
In this study, heterostructure Pd/ZnO nanocomposites with different weight contents of the loaded Pd have been successfully synthesized by sonochemical-deposition method and used as a photocatalyst for methylene blue (MB) and methyl orange (MO) degradation. The products have been characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDS), Fourier transform infrared (FTIR) spectroscopy, UV-visible spectrophotometry, photoluminescence (PL) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The products have been composed of face-centered-cubic metallic Pd0 nanoparticles with size of 40–90 nm supported on the surface of hexagonal ZnO microstructure flowers. UV-visible absorption of the heterostructure Pd/ZnO nanocomposites has been improved by the surface plasmon resonance (SPR) effect at the Pd/ZnO interface. Photocatalytic activity of the heterostructure 5% Pd/ZnO nanocomposites has been used to degrade methylene blue (MB) and methyl orange (MO) is the highest because the loaded Pd nanoparticles play the role in capturing the photo-excited electrons and the charge separation is strengthened. The heterostructure 5% Pd/ZnO nanocomposites are very stable within five-cycle test and $$^{\bullet }{\text{O}}_{2}^{ - }$$ is an active radical used for the photocatalytic process.