Surface-Integrating Oxygen Vacancy and CuO Nanodots Enabling Synergistic Electric Field and Dual Catalytic Sites Boosting CO Photoreduction.

High carrier separation efficiency and rapid surface catalytic reaction are crucial for enhancing catalytic CO photoreduction reaction. Herein, integrated surface decoration strategy with oxygen vacancies (Ov) and anchoring CuO (1 < x < 2) nanodots below 10 nm is realized on BiMoO for promoting CO photoreduction performance. The charge interaction between Ov and anchored CuO enables the formation of enhanced internal electric field, which provides a strong driving force for accelerating the separation of photocharge carriers on the surface of BiMoO (η ≈71%). They can also cooperatively reduce the surface work function of BiMoO, facilitating the migration of carrier to the surface. Meanwhile, surface-integrated Ov and CuO nanodots allowing dual catalytic sites strengthens the adsorption and activation CO into *CO over BiMoO, considerably boosting the progression of CO conversion process. In the absence of co-catalyst or sacrificial agent, BiMoO with Ov and CuO nanodots achieves a photocatalytic CO generation rate of 12.75 µmol g h, a remarkable increase of over ≈15 times that of the original counterpart. This work provides a new idea for governing charge movement behaviors and catalytic reaction thermodynamics on the basis of synergistic improvement of electric field and active sites by coupling of the internal defects and external species.