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. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

The coupling of ferroelectric and photoexcitation can effectively enhance the catalytic performance of semiconductors. By utilizing the spontaneous polarization of strong ferroelectric materials to induce the separation of electrons and holes, directly developing ferroelectrics as photocatalysts shows great promise. In this study, a ferroelectric layered perovskite Bi4Ti3O12 was prepared through molten salt method (BTO-1) and hydrothermal method (BTO-2), and it exhibits excellent photocatalytic performance for CO2 reduction. Compared to BTO-2, BTO-1 shows stronger photoexcited carrier separation ability and larger specific surface area, leading to significantly higher CH3OH and CH3CH2OH yields. The exceptional ferroelectric properties of BTO-1, resulting from its remarkable crystallinity, effectively reduce the recombination of photogenerated carriers induced by an electric field, thereby greatly enhancing its photocatalytic performance. The yields of CH3OH and CH3CH2OH after CO2 reduction by polarized BTO-1 are 1.84 and 1.61 times higher than those of unpolarized BTO-1, respectively. This study opens up new possibilities for utilizing ferroelectric materials as efficient photocatalysts to improve photocatalytic ability.