Synthesis of Titanium Dioxide Nanoparticles with Mesoporous Anatase Wall and High Photocatalytic Activity

Abstract

Mesoporous titanium dioxide nanosized powder with high specific surface area and anatase wall was synthesized via hydrothermal process by using cetyltrimethylammonium bromide (CTAB) as surfactant-directing agent and pore-forming agent. The resulting materials were characterized by XRD, nitrogen adsorption, FESEM, TEM, and FT-IR spectroscopy. The as-synthesized mesoporous TiO₂ nanoparticles have mean diameter of 17.6 nm with mean pore size of 2.1 nm. The specific surface area of the as-synthesized mesoporous nanosized TiO₂ exceeded 430 m²/g and that of the samples after calcination at 600 °C still have 221.9 m²/g. The mesoporous TiO₂ nanoparticles show significant activities on the oxidation of Rhodamine B (RB). The large surface area, small crystalline size, and well-crystallized anatase mesostructure can explain the high photocatalytic activity of mesoporous TiO₂ nanoparticles calcined at 400 °C.