A novel Bi4O5Br2/Bi24O31Br10/Bi2SiO5 heterostructure photocatalyst was synthesized successfully by in situ ion exchange reaction using BiOBr microspheres as the starting material for the first time. The heterostructured semiconductor showed superior photocatalytic activity in visible light degradation of phenol compared to pure BiOBr and other reported Bi-based photocatalysts. The exceptional photocatalytic activity of the heterostructured system can be attributable to the well-aligned straddling band-gap structures which can promote the flow of charge carriers via the heterojunction, extended light absorbance and a large Brunauer-Emmett-Teller (BET) specific surface area. The present work also proves that engineering of heterojunctions with high matching of lattices and well-aligned straddling band-structures is a significantly efficient way to achieve photocatalysts with high photocatalytic activity. (C) 2015 Elsevier B.V. All rights reserved.