Remarkable charge separation and photocatalytic efficiency enhancement through TiO2(B)/anatase hetrophase junctions of TiO2 nanobelts.

Light harvesting and charge separation are both significant to the photocatalysis, but it is challenging to synchronously realize both in a single-component material. The surface coarsened TiO 2 nanobelts with TiO 2 (B)/anatase hetrophase junctions and large BET surface area are prepared via a hydrothermal/annealing method. The presence of surface coarsened nanobelt structure enhances the light absorption through reflection/refraction of light. The TiO 2 (B)/anatase hetrophase junctions can efficiently promote the separation of photoinduced electrons and holes pairs and therefore decrease the charge recombination. The large BET surface area provides abundant active sites for the absorption and diffusion of reactants. As a consequence, the obtained TiO 2 nanobelts exhibit an enhanced photocatalytic H 2 evolution activity at the optimal annealing temperature (450 °C) with Pt as co-catalysts (0.786 mmol h−1g−1), exceeding that of pure anatase TiO 2 nanobelts (TiO 2 nanobelts-600 °C, 0.265 mmol h−1g−1). Interestingly, TiO 2 nanobelts-450 °C still show a high hydrogen evolution rate of 0.601 mmol h−1g−1 in the absence of co-catalysts. Image 1 • TiO 2 nanobelts with TiO 2 (B)/anatase hetrophase junctions are prepared. • The surface coarsened nanobelt structure enhances the light absorption through reflection/refraction of light. • The TiO 2 (B)/anatase hetrophase junctions can efficiently promote the separation of photoinduced carriers. • TiO 2 nanobelts-450 °C are highly active for producing hydrogen at 0.786 mmol h−1g−1 with Pt as co-catalysts. • TiO 2 nanobelts-450 °C still show a high hydrogen evolution rate of 0.601 mmol h−1g−1 in the absence of co-catalysts. [ABSTRACT FROM AUTHOR]