One-pot synthesis of Bi2TiO4F2/BiOBr ferroelectric heterostructure for photocatalytic oxygen evolution

•BiOBr/Bi2TiO4F2 ferroelectric heterojunction was obtained via a facial one-pot hydrothermal method.•The forming process of the BiOBr/ Bi2TiO4F2 heterojunction was investigated.•The O2 production rate of the BiOBr/ Bi2TiO4F2 heterojunction reaches 875 μmol/(g.h)•The ferroelectric spontaneous polarization of Bi2TiO4F2 played a crucial role in the oxygen evolution process. The internal electric field of ferroelectric materials originated from its spontaneous polarization can effectively improve the efficiency of carrier separation. Heterostructure formed by combining ferroelectric materials with semiconductor can further strengthen the photocatalytic property. In this work, ferroelectric material Bi2TiO4F2 has been successfully grown on the BiOBr {001} facet by a facial one-pot hydrothermal synthesis. Benefiting from both the internal electric field derived from the ferroelectric spontaneous polarization of Bi2TiO4F2, and the high-quality heterojunction interface, the O2 production rate of BiOBr/ Bi2TiO4F2 heterojunction reaches 875 μmol g−1 h−1. The possible formation process and reaction mechanism has also been discussed. This research may provide us with some new hints to design new heterostructure photocatalytic materials with both ferroelectricity and active exposure surfaces.