Synthesis and performance assessment of semiconductor photocatalysts

• Main Author: Lau, Wei Siew.
• Other Authors: Chen Zhong
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Materials::Nanostructured materials
• Online Access: http://hdl.handle.net/10356/43730
• Institution: Nanyang Technological University

A combination technique of sol-gel and hydrothermal treatment was used to synthesize nitrogen doped TiO2-based photocatalysts at different hydrothermal temperature and time. Photocatalytic activities of synthesized photocatalysts were determined by photocatalytic degradation of methylene blue in comparison with commercial P25. Based on photocatalytic degradation experiment, it was concluded that dual-phase photocatalyst, which contains both anatase and titanate phases, showed the best results under UV and visible light region as well as dark conditions, as compared to P25. A temperature study was done and it was found that with increasing hydrothermal temperature, titanate phase formed at lower temperatures were transformed to anatase phase at higher temperatures, so as to lower the total energy of the system. It was also observed that with increasing hydrothermal duration, there was an enhancement of crystallinity which improves the adsorption and degradation rates of photocatalytic activity. In addition, with longer time, photocatalysts will transform to anatase phase at a lower temperature. Hence, dual phase composition is required for ideal degradation and adsorption activity.