Oriented Assembly of Unique Mesoporous Titania Conoids for Photo-assisted Sn-Air Battery

Abstract

Mesoporous nanomaterials with unique architectures have attracted extensive research interest due to the incorporated delicate morphology and mesoporosity. However, fundamental investigation in creating specific mesoporous structures with crystalline scaffolds, like TiO₂, currently remains infertile and challenging. Herein, an unprecedented type of conical-shaped mesoporous TiO₂ configuration through ingenious oriented self-assembly in pressure is reported. The obtained mesoporous TiO₂ nano-cones have a unique shape at ≈2 µm in diameter, radially aligned rutile frameworks, and good porosity (a high surface area of 79 m² g⁻¹ and a mean pore size of 12.4 nm). By adjusting the hydrothermal time, such a facile method further allows for the manipulation of the taper size of TiO₂ conoids. By further adding n-butanol solvent to tune internal vapor pressure, mesoporous TiO₂ with different architectures (concave, cleft, smooth spheres) can also be constructed. The combination of the nanoscopic and mesoscopic features favors effective mass transportation and reactant access, giving rise to high performances in photo-assisted rechargeable Sn-air batteries. The study is envisaged to afford an exciting pathway for the design and synthesis of specific mesostructures, nano-architectures, and complex hierarchies toward future technologies.