Photocatalytic nanostructures : synthesis and characterization

• Main Author: Low, Pearlie SiJia.
• Other Authors: Chen Zhong
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Materials::Nanostructured materials
• Online Access: http://hdl.handle.net/10356/44011
• Institution: Nanyang Technological University

A photocatalyst is utilized to perform enhanced degradation of pollutants to harmless by-products under irradiation of a light source. Of which, Titanium Dioxide is the widely known semiconductor photocatalyst. In this work, Sodium Titanate which has a semi-open nanotubular structure was synthesized by hydrothermal method as the starting material to undergo ion-exchange with Silver and Copper ions.. Transition-metal Copper Titanate formed via the Solution-based ion-exchanged method showed minimal photodegradation performance of Methyl Orange (MO) under irradiation of UV-light. Post-annealing of samples was done to investigate the presence of the photoactive anatase phase and in relation to the photodegradation performance in MO. Sodium Titanate was made to interact to form Silver Titanate via two ion-exchanged methods (Solution-based : AgT and Solid-state : SSAg ). These Silver Titanates showed enhanced photodegradation performance in MO solution under UV-light surpassing that of Degussa P25. Silver Titanates was also found to be photoactive under visible-light irradiation for degradation of MO. Characterization of these titanate samples were analyzed with X-ray Diffraction (XRD) patterns and Diffuse Reflectance Spectra (DRS) results which showed insights to the changes in phases and the improvement of the band gap energy respectively. Sample AgT was also tested for its photostability and results showed a need for improvement. This study demonstrates simple ion-exchange methods to obtain enhanced photodegradation performance in visible-light region.