Synthesis and Characterization of ZnO Doped with Gold Nanoparticles for Improved Photocatalytic Activity

Recently, gold nanoparticles have been widely employed to achieve the activation of the catalytic properties of semiconductors for the decomposition of organic dyes. In this study, gold nanoparticles were prepared by Turke-vich method using HAuCl4 and trisodium citrate dehydrate. gold nanoparticles with size of 18, 20, and 22 nm were prepared by controlling the trisodium citrate dehydrate concentration and reaction time. Furthermore, ZnO nanorods were prepared using zinc nitrate hexahydrate through a hydrothermal process. Finally, ZnO doped with gold nanoparticles nanocomposite photocatalysts were prepared by mixing ZnO and gold nanoparticles and drying at 60 °C. The photocatalytic activity of the nanocomposites was evaluated through the degradation of Rhodamine B dye under solar light. ZnO doped with 22 nm of gold nanoparticles showed the highest photocatalytic activity, providing up to 78.6% dye degradation. The highest photocatalytic activity of the ZnO doped with 22 nm of gold nanoparticles nanocomposite was probably due to the increased surface plasmon resonance effect of the gold nanoparticles.