Soft-Template Synthesis of Mesoporous Anatase TiO2 Nanospheres and Its Enhanced Photoactivity

Highly crystalline mesoporous anatase TiO2 nanospheres with high surface area (higher than P25 and anatase TiO2) are prepared by a soft-template method. Despite the high specific surface area, these samples have three times lower equilibrium adsorption (<2%) than Degussa P25. The rate constant of the mesoporous anatase TiO2 (0.024 min(-1)) reported here is 364% higher than that of P25 (0.0066 min(-1)), for the same catalytic loading. The results of oxidation-extraction photometry using several reactive oxygen species (ROS) scavengers indicated that mesoporous anatase TiO2 generates more ROS than P25 under UV-light irradiation. This significant improvement in the photocatalytic performance of mesoporous spherical TiO2 arises from the following synergistic effects in the reported sample: (i) high surface area; (ii) improved crystallinity; (iii) narrow pore wall thicknesses (ensuring the rapid migration of photogenerated carriers to the surface of the material); and (iv) greater ROS generation under UV-light.