Bismuth oxyhalide quantum dots modified sodium titanate necklaces with exceptional population of oxygen vacancies and photocatalytic activity

We here demonstrate the controlled synthesis of BiOBr quantum dots (QDs) decorated Na2Ti3O7 necklaces via a hydrothermal transformation of sodium titanate nanotubes. The BiOBr QDs are deposited on the surface of Na2Ti3O7 necklaces, forming a heterogeneous interface of BiOBr(200) and Na2Ti3O7(110), which promotes the separation efficiency of photogenerated charges, thus resulting in its superior catalytic performance in the photo-oxidation of benzyl alcohol. The BiOBr/Na2Ti3O7-1.0 exhibiting highest oxygen defect population gives best photocatalytic activity with a promising conversion rate of 3.32 mmolreacted BA gcatal.-1h-1, which is substantially higher than the corresponding reported photocatalysts. DFT results corroborate the superior performance of BiOBr/Na2Ti3O7 is mainly due to the formation of a built-in electric field and given efficiently the charge transfer between BiOBr(200) and Na2Ti3O7(110). In all, this study reports a simple in-situ hydrothermal growth protocol to efficiently construct BiOBr/Na2Ti3O7 heterojunction composites and offers guidelines for design of a new synthetic strategy to prepare efficient photocatalysts.