Controllable synthesis of Bi2WO6(001)/TiO2(001) heterostructure with enhanced photocatalytic activity

Photocatalysts with exposed specific active facets usually exhibit desirable photocatalytic activity. These active crystal facets offer various advantages that are often ignored. In this work, we employed specific exposed crystal facets as substrate to construct an excellent heterostructure for high-efficiency photocarrier transformation channel. The (001) face of anatase TiO2 was selected to fabricate the composite (001) Bi2WO6 as Bi2WO6(001)/TiO2(001) heterostructure. The lattice spacing of {110} facets of TiO2 (0.26741 nm) in the heterostructure was very close to that of {020} (0.27180 nm) or {200} facet (0.27285 nm) of Bi2WO6. Thus, (001) Bi 2WO(6) grew on the (001) faces of anatase TiO2 with little lattice compression between the {020} and {200} facets. Bi2WO6 nanocrystal could not grow on the (101) faces of P25, which confirms that the {001} facet of the substrate is the critical factor for constructing the heterostructure. The Bi2WO6(001)/TiO2(001) heterostructure was confirmed to be an ideal transmission channel that extended the separation time of photocarriers and enhanced the photocatalytic activity. Thus, an improved strategy that employs specific crystal facet substrate is proposed to construct a heterostructure for high-efficiency photocarrier transformation channel. (C) 2016 Elsevier B.V. All rights reserved.