Synergistic Polarization Engineering on Bulk and Surface for Boosting CO₂ Photoreduction

Sluggish charge kinetics and low CO 2 affinity seriously inhibit CO 2 photoreduction. Herein, the synchronous promotion of charge separation and CO 2 affinity of Bi 4 Ti 3 O 12 is realized by coupling corona poling and surface I‐grafting. Corona poling enhances ferroelectric polarization of Bi 4 Ti 3 O 12 by aligning the domains direction, which profoundly promotes charge transfer along opposite directions across bulk. Surface I‐grafting forms a surface local electric field for further separating charge carriers and provides abundant active sites to enhance CO 2 adsorption. The two modifications cooperatively further increase the ferroelectric polarization of Bi 4 Ti 3 O 12 , which maximize the separation efficiency of photogenerated charges, resulting in an enhanced CO production rate of 15.1 μmol g −1 h −1 (nearly 9 times) with no sacrificial agents or cocatalysts. This work discloses that ferroelectric polarization and surface ion grafting can promote CO 2 photoreduction in a synergistic way.