Effect of Heat Treatment on the Micro-structural, Crystallinity and Photocatalytic Properties of Hydrothermally Prepared Titanate Nanowires

摘要

Titanate nanowires were synthesized by hydrothermal process in 10 M NaOH aqueous solution at 200°C for 24 h. The samples were washed repeatedly in HCl aq. solution and deionized water until pH ～7. Subsequently, the samples were heat-treated at 400-850°C in air for 2 h. The X-ray Diffraction (XRD) analysis of the sample heat-treated at 800°C showed the crystalline structure of sodium titanate (Na_2Ti_6O_(13)), while the presence of anatase phase was detected from the sample that was heat-treated at 850°C. Wire-like morphology of the synthesized sample was observed using FE-SEM. The photocatalytic activity of the samples heat-treated at 600, 800, 850°C and 900°C was investigated by measuring the degradation of methylene blue (MB) in aqueous solution under UV-light irradiation and more than 90% of the dye was efficiently degraded by the sample heat-treated at 850°C within 45 minutes irradiation time as compared to other tested samples.