Synthesis of uniform ordered mesoporous TiO2 microspheres with controllable phase junctions for efficient solar water splitting

摘要

As a benchmark photocatalyst, commercial P25–TiO _(2) has been widely used for various photocatalytic applications. However, the low surface area and poorly porous structure greatly limit its performance. Herein, uniform ordered mesoporous TiO _(2) microspheres (denoted as Meso-TiO _(2) - X ; X represents the rutile percentage in the resultant microspheres) with controllable anatase/rutile phase junctions and radially oriented mesochannels are synthesized by a coordination-mediated self-assembly approach. The anatase/rutile ratio in the resultant microspheres can be facilely adjusted as desired (rutile percentage: 0–100) by changing the concentration of hydrochloric acid. As a typical one, the as-prepared Meso-TiO _(2) -25 microspheres have a similar anatase/rutile ratio to commercial P25. But the surface area (78.6 m ~(2) g ~(?1) ) and pore volume (0.39 cm ~(3) g ~(?1) ) of the resultant microspheres are larger than those of commercial P25. When used as the photocatalyst for H _(2) generation, the Meso-TiO _(2) -25 delivers high solar-driven H _(2) evolution rates under air mass 1.5 global (AM 1.5 G) and visible-light ( λ > 400 nm), respectively, which are significantly larger than those of commercial P25. This coordination-mediated self-assembly method paves a new way toward the design and synthesis of high performance mesoporous photocatalysts.