Synthesis and Characterization of Hierarchical Structure Au/ZnO Nanocomposites for Possible Photocatalytic Applications

Abstract

Semiconductor-metal nanocomposites are actively investigated for their diverse applications in emerging fields such as photocatalysis, photovoltaics, and chemical sensing. In this study, we synthesized ZnO semiconductor nanoparticles using a chemical bath deposition method with ZnSO4·7H2O and controlled NH4OH concentrations, facilitated by an anionic surfactant to enable the attachment of Au metal nanoparticles. Au nanoparticles were prepared from HAuCl4 using citrate as a reducing agent, and metal oxide was rapidly introduced to ensure a well-defined nanocomposite with a fixed 75 w/v% composition. Fast Fourier transform spectroscopy (FTIR) and Ultra-visible (UV-Vis) spectroscopy were used to provide clear evidence of Au/ZnO nanocomposite formation through the presence of distinctive peaks around 359nm and 518nm, with Dynamic Light Scattering (DLS) revealing contrasting average sizes for ZnO and Au, highlighting the significant size difference in the Au/ZnO nanocomposites. Additionally, the scanning electron microscopy – energy dispersive x-ray (SEM-EDS) analysis confirmed the successful presence of ZnO nanoparticles. These findings offer insights into the potential applications and unique properties of Au/ZnO nanocomposites for possible photocatalytic applications.