Synergistic Polarization Engineering on Bulk and Surface for Boosting CO 2 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.
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