Self-induced synthesis of phase-junction TiO(2) with a tailored rutile to anatase ratio below phase transition temperature

The surface phase junction of nanocrystalline TiO(2) plays an essential role in governing its photocatalytic activity. Thus, facile and simple methods for preparing phase-junction TiO(2) photocatalysts are highly desired. In this work, we show that phase-junction TiO(2) is directly synthesized from Ti foil by using a simple calcination method with hydrothermal solution as the precursor below the phase transition temperature. Moreover, the ratio of rutile to anatase in the TiO(2) samples could be readily tuned by changing the ratio of weight of Ti foil to HCl, which is used as the hydrothermal precursor, as confirmed by the X-ray diffraction analysis. In the photocatalytic reaction by the TiO(2) nanocomposite, a synergistic effect between the two phases within a certain range of the ratio is clearly observed. The results suggest that an appropriate ratio of anatase to rutile in the TiO(2) nanocomposite can create more efficient solid-solid interfaces upon calcination, thereby facilitating interparticle charge transfer in the photocatalysis.