Synthesis of Au/ZnO nanocomposite and Au:ZnO core:shell via laser ablation for of photo-catalytic applications

The pulsed laser ablation technique is a safe and eco-friendly method, this technique was used to prepare gold (Au) and zinc oxide (ZnO) in two forms, both as core:shell nanoparticles (CS NPs) and a nanocomposite (NC). The absorption behaviour for Au/ZnO NCs and Au:ZnO CS NPs was investigated the UV-visible of Au NPs peak at 525 nm whiles the peak of the ZnO NPs at 375 nm. Transmission electron microscope (TEM) images show the average size of Au NPs is 30–45 nm adhering to ZnO NPs with an average size of 55–60 nm. In Au/ZnO CSNPs, Au acts as a core while the ZnO nanoparticles produced a shell; in spherical gold nanoparticles, the average shell thickness of ZnO is 10–15 nm. As synthesised, the Au:ZnO CSNPs are endowed with high photocatalytic activity even after multiple cycles of photo-catalytic reactions when compared with Au/ZnO NCs.