Ferroelectric polarization promotes the excellent CO2 photoreduction performance of Bi4Ti3O12 synthesized by molten salt method

The coupling of ferroelectric and photoexcitation is an effective strategy to improve semiconductor catalytic performance. Given the fact that the spontaneous polarization of strong ferroelectric materials can induce the separation of electrons and holes, the direct development of ferroelectrics as photocatalysts can be a promising approach. Herein, a kind of ferroelectric layered perovskite Bi4Ti3O12 is prepared by molten salt method (BTO-1) and hydrothermal method (BTO-2) as an efficient photocatalyst for the reduction of CO2. Compared with BTO-2, BTO-1 exhibits stronger photoexcited carriers separation ability and larger specific surface area, consequently the reduction performance of BTO-1 is 1.81 and 1.68 times of BTO-2 for CH3OH and CH3CH2OH yield, respectively. Moreover, BTO-1 has excellent ferroelectric properties due to its remarkable crystallinity, subsequently ferroelectric polarization induced by electric field greatly reduces the recombination of photogenerated carriers, thus greatly improving the photocatalytic performance of polarized BTO-1. The yields of CH3OH and CH3CH2OH after reduction of CO2 by BTO-1 are 1.84 and 1.61 times that of unpolarized BTO-1 separately. This result provides more possibilities for directly using ferroelectric materials as efficient photocatalysts to improve the photocatalytic ability.