Assembly of surface-defect single-crystalline strontium titanate nanocubes acting as molecular bricks onto surface-defect single-crystalline titanium dioxide (B) nanorods for efficient visible-light-driven photocatalytic performance.

Ti self-doped single-crystalline SrTiO nanocubes acting as molecular bricks are successfully assembled onto Ti self-doping single-crystalline TiO(B) nanorods through an effortless two-step hydrothermal process coupled with an in situ solid-state chemical reduction method. SrTiO nanocubes act as molecular bricks, which are uniformly assembled onto the surface of TiO(B) nanorods due to lattice matching. The band gap of the resultant SrTiO/TiO(B) sample is ∼2.97 eV, which exhibits excellent photocatalytic performance for the reduction of Cr(VI) and hydrogen production under visible light. The apparent rate constant k value for the photocatalytic reaction of SrTiO/TiO(B) for Cr(VI) reduction is ∼8 times higher than that of white TiO(B). The photocatalytic hydrogen production rate for SrTiO/TiO(B) is ∼160.2 μmol g h, which is ∼5 times higher than that of white TiO(B). The enhanced photocatalytic activity can be considered to be caused by a synergetic effect of heterojunction formation and the introduction of Ti self-doping, which can not only facilitate the separation of photogenerated charge carriers between TiO(B) and SrTiO, but also broaden the photoresponse from the UV to visible-light region.