Charge‐Polarized Dual Sites on BiO 1– x Cl Nanosheets Facilitate C─C Coupling via Dipole Enhancement Mechanism for CO 2 −to─CH 3 COOH Photoconversion

ABSTRACT The photocatalytic conversion of CO 2 into acetic acid without sacrifice agent remains a challenge, primarily due to multiple steps of electron and proton transfers as well as sluggish C─C coupling kinetics. Herein, we synthesize abundant charge‐asymmetry dual Bi sites on defective BiO 1– x Cl nanosheets via solvothermal approach. The dipole moment between Bi pairs has been further increased upon the modification of CuO nanoparticles. This catalyst has exhibited a CH 3 COOH production rate of 173.0 µmol g −1 h −1 with the selectivity of 98.3%, and no discern deactivation after 20 cycles of CO 2 photoreduction measurement. The combined analysis of characterizations and theoretical calculations reveals that the formulation of oxygen vacancies and addition of CuO induce electronic rearrangement at the exposed dual Bi centers, forming electron‐rich and electron‐deficient pairs. Mechanism studies interpret that this unique asymmetric electron structure not only accelerates the separation and migration of photogenerated electron–hole pairs through the inherent dipole field, but also significantly enhances C─C coupling efficiency during CO 2 reduction. This study provides a design strategy of the advanced material for asymmetrical photocatalysis.