Synthesis, characterization of metal-doped ZnO nanostructures, and investigation of their photocatalytic activities

Photocatalytic degradation is one of the most important methods used to degrade and remove organic pollutants that cause environmental and water pollution. Zinc oxide (ZnO) is one of the metal oxide semiconductor materials that is prominent as a photocatalyst. Surface area and metallic doping factors have significant effects on the photocatalytic activity of ZnO. In this thesis, ZnO nanostructures, both undoped and doped with hafnium (Hf) metal in the concentration range of 1 – 5 mol %, were produced separately in powder and thin film forms. The production of powder samples was carried out by the sol-gel method. Thin film samples were produced by the sequential application of sol-gel spin coating and hydrothermal methods. The crystallographic structure of the produced samples was determined by XRD, the surface and morphological properties were investigated by FE-SEM, and the optical transmittance properties were investigated by UV-Vis spectrophotometer. The effect of the produced samples on the photocatalytic degradation of bromocresol green dye was monitored by spectrophotometer. It was determined that the 5 mol % Hf doped ZnO nanostructured powder sample degraded the bromocresol green solution by 62 % at t = 140 min. under UV light. It was determined that the 2 mol % Hf doped ZnO nanostructured thin film degraded the bromocresol green solution by 65 % at t = 150 min. under UV light.