Towards new generation of sustainable catalysts:Study of shape and size controlled TiO2 nanoparticlesin photocatalytic degradation of industrial dye

Due to industrialization and population growth, environmental contamination caused by organic pollutants is becoming an increasing problem worldwide. Environmental pollution on a global scale, particularly water pollution, has drawn scientists’ attention to the vital need for environmentally clean and friendly chemical processes. The demand for higher quality water has increased due to population growth, more stringent health regulations and economic development. Untreated wastewater contains a variety of organic compounds with variable toxicities as well as carcinogenic and mutagenic properties. Most contaminants in wastewater contain aromatic rings, which are generally resistant to chemicals, photochemicals and biological degradation.These compounds are very persistent in the environment and have a high potential to negatively affect human health and the ecosystem. Therefore, the removal or degradation of hazardous material and contaminants from wastewater is a significant global challenge. This thesis reported on the synthesis of titanium dioxide by using a peroxo method. This synthesis was done in the presence of a number of fluoride-containing surfacemodifying agents to determine the effects of these agents on particle growth, shape and crystallinity. Further, studies were carried out to investigate the modification of F-modified TiO2 with the deposition of Au colloids and an Au9 cluster. A different deposition method is employed in the synthesis of the TiO2-Au materials to gain a catalyst with the highest photocatalytic activity. The performance of the catalyst was further investigated through pre-treatment and post-treatment of the materials. Finally, several of the synthesised materials were trialled as photocatalysts using industrial dye Reactive Blue 19 (RB19) as an organic pollutant