Synthesis of uniform ordered mesoporous TiO 2 microspheres with controllable phase junctions for efficient solar water splitting

Abstract

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 (? > 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. - 2019 The Royal Society of Chemistry.