Engineering heterostructured Ti4O5/BaTiO3 ferroelectric by surface reconstruction for enhanced photocatalytic CO2 reduction

Abstract

Efficient separation of electrons and holes in photocatalysis plays a key role in achieving high efficiencies of CO₂ reduction. The available built-in electric field could separate the photogenerated charges and thus improve the photocatalytic activity. Here, we have developed a high-quality ferroelectric heterostructure by surface reconstruction engineering, where Ti₄O₅ with a 3–4 unit-cell thickness is epitaxially grown on BaTiO₃. In these heterostructures, ferroelectric polarization regulates the contact potential between interfaces and greatly accelerates electron transport. Benefiting from the manipulation of ferroelectric polarization, the heterostructures possess a high CO₂ reduction activity, with a CO production rate of 11.8 μmol g⁻¹ h⁻¹, which is almost 10 times higher than that of pristine BaTiO₃ nanoparticles. This work provides a new avenue for fabricating ferroelectric heterostructures based on surface reconstruction, enhancing their potential for photocatalytic CO₂ reduction.