Regulating the Built-In Electric Field of BiOBr by a Piezoelectric Mineral Tourmaline and the Enhanced Photocatalytic Property

The prospective strategy to control the electrochemical properties of photocatalysts involves the spontaneous polarization characteristics of ferroelectric materials to adjust the electronic structure of the interface. Herein, we report that the polarization of the BiOBr (BOB) photocatalyst is able to be regulated by the induction of a piezoelectric mineral tourmaline and the enhanced photocatalytic property. The BiOBr photocatalyst with a preferable exposure of high active facet can be synthesized. The built-in electric field can be regulated with various amounts of a piezoelectric mineral tourmaline during the synthesis process. It can be found that the photocatalytic properties toward degradations for both Rhodamine B dye and a colorless phenol pollutant with xenon lamp illumination at room temperature over the composite tourmaline/BiOBr improved effectively as compared to those of pure BiOBr. 2%T/BOB photocatalyst showed the best performance and the overall decomposition of the pollution is twice that of the pure BOB. The results demonstrated that the spontaneous polarization effect of tourmaline led to the variation in the built-in electric field of BiOBr, which facilitated the separation and transport of photogenerated charges and enhanced the photocatalytic properties.