Formation and Evaluation of Au/ZnO Particles by a Spray Pyrolysis Method

Abstract

ZnO/Au is expected to exhibit catalytic properties by absorbing ultraviolet and visible light because ZnO and Au nanoparticles can absorb ultraviolet and visible light, respectively. Doping studies on Au nanoparticles on ZnO (ZnO/Au) have been conducted to expand the absorption wavelength range. This study generates ZnO/Au particles by an ultrasonic spray pyrolysis method (USP). To prevent particle aggregation, Triton X-100, a non-ionic surfactant, is added, and its effects are examined. The generated ZnO/Au particles are characterized using different methods. SEM reveals the particle size is several micrometers, while XRD analysis indicates that ZnO and a metallic Au crystalline are present. The TEM images of the particles show that the Au crystals are well dispersed in the inner and outer portions of ZnO. UV-Vis spectroscopy confirms that the smaller the Au particle size, the higher the visible absorption peak near 400 nm. Adding Triton X-100 shifts the absorption peak toward the longer wavelength side but improves the aggregation of Au particles.