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(2 0 0) and Na2Ti3O7(1 1 0), 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 mmol(reacted) BA g(catal.)(-1)h(-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(2 0 0) and Na2Ti3O7(1 1 0). 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. (C) 2022 Elsevier Inc. All rights reserved.