Branched Mesoporous TiO2 Mesocrystals by Epitaxial Assembly of Micelles for Photocatalysis
Cell Reports Physical Science
Zhang et al. demonstrate a crystallization-driven oriented assembly approach from monomicelles to construct branched mesoporous TiO 2 mesocrystals. The multipods primarily consist of arms along crystal directions and ordered open mesochannels arranged in parallel along the growth direction of each arm, and they are efficient photocatalysts. The oriented assembly of monomicelle strategy provides insight into developing programmable mesoporous semiconductors with coherent atomic domains and
... c domains and mesostructure. HIGHLIGHTS Branched mesoporous TiO 2 mesocrystals with coherent crystal structure are prepared Crystallization-driven epitaxial assembly strategy from monomicelles is demonstrated The mesocrystals show intensive carrier dynamics and efficient hydrogen evolution SUMMARY The understanding and control of the structural complexity of mesoporous semiconductors with single-crystal-like nature are both attractive and challenging. Here, we report a crystallization-driven epitaxial assembly from monomicelles to construct branched mesoporous TiO 2 mesocrystals (m-TiO 2 MCs) with coherent atomic domains. The star-shaped multipods are obtained by two-step evaporation with nanocrystal mediation, primarily consisting of arms along < 001 >, < 101 >, and < 111 > crystal directions. For each arm, ordered open mesochannels arrange in parallel along the growth direction. The m-TiO 2 MC multipods have a surface area of $116 m 2 /g and single-crystal-like frameworks and are good hydrogen evolution photocatalysts. Under full-spectrum irradiation, the branched m-TiO 2 MCs exhibit a hydrogen evolution rate of 8 mmol h À1 g À1 , which is more than four times higher than that of commercial TiO 2 P25. This crystallization-driven self-assembly approach may provide valuable insight into designing programmable mesoporous mesocrystals by controlling the oriented assembly of monomicelle building blocks.