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

Abstract

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 TiO2 nanobelts with TiO2(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 TiO2(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 TiO2 nanobelts exhibit an enhanced photocatalytic H2 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 TiO2 nanobelts (TiO2 nanobelts-600 °C, 0.265 mmol h−1g−1). Interestingly, TiO2 nanobelts-450 °C still show a high hydrogen evolution rate of 0.601 mmol h−1g−1 in the absence of co-catalysts.