Synthesis and photocatalytic activity of doped tantalates

• Main Author: Muhammad Irwan Ratman.
• Other Authors: Chen Zhong
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Engineering::Materials::Material testing and characterization
• Online Access: http://hdl.handle.net/10356/44673
• Institution: Nanyang Technological University

Sodium tantalate (NaTaO3) is studied intensively for its high photocatalytic activity. However, NaTaO3 photocatalysts work under ultraviolet (UV) light. Since visible light accounts for more than 40% of solar energy, visible-light-driven photocatalysts have attracted more attention in recent years. Doping has been proven to be a feasible method to prepare visible-light-driven photocatalysts. Recently, anion doping of nitrogen, sulphur and carbon has been extensively investigated. The aim of this study is to investigate the effect of sodium sulphide (Na2S) on sodium tantalate nanoparticles via hydrothermal technique. The effect of sulphur diffusion in sodium tantalate at high temperatures was also studied. The synthesis of sodium tantalates maintained in sulphur-rich conditions was carried out via both hydrothermal technique and solid-state synthesis. The resulting products was characterised by Scanning Electron Machine (SEM), Energy-dispersive X-ray Spectroscopy (EDX) and X-ray Diffractometer (XRD) and evaluated by UV-vis Diffuse Reflectance Spectroscopy (DRS). The photocatalytic hydrogen evolution was evaluated by gas chromatography. Sulphur-doping of NaTaO3 photocatalyst resulted in changes in the morphology and crystallite size of NaTaO3. It was also found that S-doped NaTaO3 have the ability to produce hydrogen gas in the presence of methanol under UV-light irradiation.