Regulation of ferroelectric polarization and reduced graphene oxide (RGO) synergistically promoting photocatalytic performance of Bi3TiNbO9

Efficient separation and transfer of photogenerated electron-hole pairs is an intriguing but challenging assignment in design photocatalysts with excellent performance. However, low carrier separation efficiency and narrow spectral response range hinder the practical application of traditional semiconductor photocatalysts. The ferroelectric semiconductors with spontaneous intrinsic electric polarization could efficiently accelerate the photogenerated carrier separation and transfer. Here, the heterojunction photocatalysts coupled with ferroelectric Bi3TiNbO9 and reduced graphene oxide (RGO) were synthesized for hydrogen evolution and organic pollutant degradation. The ferroelectric polarization of BTNO is modulated by La3+ ion doping and verified by the hysteresis loop and density functional theory calculations. Results indicated that the enlarged ferroelectric polarization could be realized through doping La3+ ion, which ultimately improves the photocatalytic performance and delivers a significant enhancement for RhB degradation efficiency and H2 evolution rate. This work provides guidance for constructing composite photocatalysts by implanting ferroelectrics to achieve high effective photocatalysts.