High surface area black TiO2 templated from ordered mesoporous carbon for solar driven hydrogen evolution

Abstract Hydrogen reduction of TiO 2 to generate surface Ti 3+ can significantly increase the photochemical activity under solar-light illumination. However, the low surface areas of commercial TiO 2 limit their photocatalytic activities. Herein, we report a high surface area ordered mesoporous black TiO 2 , which exhibits an improved photocatalytic performance. The TiO 2 material was prepared by using a highly ordered mesoporous carbon CMK-3 as a hard template, which possesses very high surface area, large pore volume and uniform mesopores. By using the advantage of pore confinement in the mesoporous carbon template, TiO 2 -carbon composites were annealed at different temperatures to investigate the influence of the crystallinity of TiO 2 on the photocatalytic hydrogen production. TiO 2 calcined at 500 °C, having a high surface area (up to 158 m 2  g −1 ), large pore volume (up to 0.62 cm 3  g −1 ), uniform pore size (5–6 nm), and anatase crystal structure, indicated the highest hydrogen generation rate. Since the TiO 2 has been treated at a higher temperature in the confinement of the mesoporous carbon, the TiO 2 can easily be reduced at 500 °C under hydrogen atmosphere to generate surface Ti 3+ species without destruction of the mesostructure and exhibits a high solar-driven hydrogen evolution rate (188 μmol h −1 ), which is more than two times higher than that of commercial TiO 2 (82 μmol h −1 ).