Controllable synthesis of Bi sub(2)WO sub(6)(001)/TiO sub(2)(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 TiO sub(2) was selected to fabricate the composite (001) Bi sub(2)WO sub(6) as Bi sub(2)WO sub(6)(001)/TiO sub(2)(001) heterostructure. The lattice spacing of {110} facets of TiO sub(2) (0.26741 nm) in the heterostructure was very close to that of {020} (0.27180 nm) or {200} facet (0.27285 nm) of Bi sub(2)WO sub(6). Thus, (001) Bi sub(2)WO sub(6) grew on the (001) faces of anatase TiO sub(2) with little lattice compression between the {020} and {200} facets. Bi sub(2)WO sub(6) 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 Bi sub(2)WO sub(6)(001)/TiO sub(2)(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.