Synergy of ferroelectric polarization and oxygen vacancy to promote CO2 photoreduction
Abstract Solar-light driven CO 2 reduction into value-added chemicals and fuels emerges as a significant approach for CO 2 conversion. However, inefficient electron-hole separation and the complex multi-electrons transfer processes hamper the efficiency of CO 2 photoreduction. Herein, we prepare ferroelectric Bi 3 TiNbO 9 nanosheets and employ corona poling to strengthen their ferroelectric polarization to facilitate the bulk charge separation within Bi 3 TiNbO 9 nanosheets. Furthermore, surface oxygen vacancies are introduced to extend the photo-absorption of the synthesized materials and also to promote the adsorption and activation of CO 2 molecules on the catalysts’ surface. More importantly, the oxygen vacancies exert a pinning effect on ferroelectric domains that enables Bi 3 TiNbO 9 nanosheets to maintain superb ferroelectric polarization, tackling above-mentioned key challenges in photocatalytic CO 2 reduction. This work highlights the importance of ferroelectric properties and controlled surface defect engineering, and emphasizes the key roles of tuning bulk and surface properties in enhancing the CO 2 photoreduction performance.