A general precursor strategy for one-dimensional titania with surface nanoprotrusion and tunable structural hierarchy

Abstract

The design of one-dimensional titania with tunable structural hierarchy holds exciting implications for applications such as optoelectronics, sensing and catalysis. Here, we report a general precursor strategy for one-dimensional titania with surface nanoprotrusion and tunable hierarchical structures realized via a titanate route using electrospun titania fibers as precursors. One-dimensional hierarchical hollow titanate (1D-HHT) was first fabricated under mild alkaline hydrothermal conditions from electrospun amorphous TiO2 precursors. The time-dependent evolution of 1D-HHT has been investigated in detail. The concerted effect of alkaline etching and Ostwald ripening is responsible for the surface nanoprotrusion and modulation of structural hierarchy. Anatase TiO2 with the same hierarchical structures can be obtained using controlled calcination. The as-fabricated one-dimensional titania with varying levels of structural hierarchy exhibits about 1.3–1.5 times higher power conversion efficiency than commercial P25 as a photoanode material for dye-sensitized solar cells (DSSCs). The current work may be extended for more functional TiO2-based materials with tunable structural hierarchy and could widen the application range of electrospinning technology for one-dimensional hierarchical structures.