Photocatalytic and UV-VIS Optical Properties of Titanium-Silver Doped Composite Synthesized by Hydrothermal Method

Abstract

Titanium (TiO2) has been studied and proved to be the most ideal photocatalyst due to several aspects such as high photoactivity, thermal and chemical stability, relatively inexpensive and non-toxicity. As the problem statement, the photoactivity and optical stability are the crucial aspects to synthesize an ideal photocatalyst. These aspects can be improved through the synthesize method to enhance its nanocrystal crystallinity. The purpose of this research is to synthesize the high crystalline silver-titanium (AgTiO2) nanoparticles and study its photoactivity and optical properties. The Ag-TiO2 was synthesized through the modification of caustic hydrothermal method and molten salt doping process to dope the silver nitrate (AgNO3) as a dopant agent. The photoactivity performance of high grade TiO2 and high crystallinity Ag-TiO2 were examine via a Methylene Blue Degradation (MBD) testing under both visible light and UV light. The optical properties were measured through the Surface Area BET (SBET) and UV-Vis-NIR spectrophotometer (UV-Vis). The UV-Vis results show that the 0.01%-Ag-TiO2 sample has a lowest band gap with 2.6eV compared to the commercial TiO2 (P25) and other samples. The SBET analysation shows that, the biggest surface area was formed in 0.05%-Ag-TiO2 followed by 0.01%-Ag-TiO2, un-doped TiO2 and 0.03%-Ag-TiO2. For the MBD-testing, the high crystalline Ag-TiO2 was performed a better photoactivity compared to the high grade TiO2. The 0.05%-Ag-TiO2 has the best crystallinity and morphology growth compared to 0.01%-Ag-TiO2 and 0.03%-Ag-TiO2 doping samples. The results obtained proves that, the presence of silver dopants was successfully improved the nanocrystal crystallinity of Ag-TiO2 and influenced its photoactivity performance.