Control of interface between anatase TiO2 nanoparticles and rutile TiO2 nanorods for efficient photocatalytic H2 generation.

In recent years, production of H 2 through photocatalytic water splitting has attracted considerable attention in the chemistry and material fields. In this work, TiO 2 based heterojunction photocatalyst, which is consisted of rutile nanorods and anatase nanoparticles, is systematically studied by controlling the HCl concentration in hydrothermal process. With the help of loaded Pt, an interesting two-peak feature (“M” shape) is observed in the HCl-dependent H 2 production efficiency. The peak values are 54.3 mmol h −1 g −1 and 74.4 mmol h −1 g −1 , corresponding to 83.9% and 12% anatase phase, respectively. A detailed analysis based on the microstructure and photoluminescence (PL) spectra indicate that the “M” shape feature is directly linked to the HCl-controlled interface area. Moreover, an unexpected zero interface area is revealed at an intermediate HCl concentration. In terms of homogeneous and heterogeneous nucleations, an interface growth mechanism is proposed to clarify its HCl-sensitive character. This work provides a route to enhance the photocatalytic activity in TiO 2 based photocatalyst via increasing the interface area. [ABSTRACT FROM AUTHOR]