Electrospun anatase TiO2 nanofibers with ordered mesoporosity

Abstract

Anatase TiO₂ nanofibers (200–300 nm in diameter) with 3-dimensionally (3D) ordered pore structure and high surface area were synthesized by electrospinning technique. The unique combination of partially acetylacetone chelated Ti-alkoxide, viscosity-controlling cum high positive charge balancing agent PVP and structure director F127 yielded nanofibers with ordered mesoporosity similar to the Pmm structure. Dynamic heating of the fibers in the temperature range 350–540 °C and simultaneous XRD studies revealed that the amorphous to anatase transformation initiated at about 400 °C with the retention of 3D mesoporosity up to the final heat-treatment stage. TEM studies also confirmed this. During amorphous to anatase conversion, the surface area decreased from 165 (350 °C) to 90 m² g⁻¹ (540 °C). The crystalline mesoporous nanofibers showed enhanced photocatalytic activity with reusability.