Preparation of Bi-doped TiO2 modified by TEA and Its Enhanced Photocatalytic Properties under visible light illumination

Bi-doped TiO2 powders were synthetised by sol-gel method and triethanolamine(TEA) was added to the Bi-doped TiO2 colloid to improve the perfenmance of prepared photocatalyst. The powder samples were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and UV-vis spectroscopy, respectively. The results show that the addition of TEA influenced both the morphology and the light absorption performance of the catalysts. The photocatalytic activity was investigated by employing methylene blue (MB) as the target pollutant under visible light illumination. Compared with Bi-doped TiO2, the samples modified by TEA exhibited an enhanced photocatalytic activity. The enhanced photocatalytic activity observed could be attributed to the porous surface and the red shift of visible light absorption which was caused by a narrowing of bandgap of semiconductor.