Atomic Intercalation – an Approach to Enhance Photogenerated Carrier Dynamics for Efficient Photocatalysis Carbon Dioxide Reduction

Visible-light-driven carbon dioxide (CO₂) reduction presents a long-term answer to environmental challenges. However, the limited effective optical carriers generated by the limited response dynamics of the existing photocatalyst have severely hindered the development of high efficiency photocatalysts. Here, we report a method of cobalt atoms intercalation in ultrathin BiOBr nanosheets for boosted photocatalytic CO₂ reduction. The experimental results show that there is a strong spatial charge transfer between the intercalated atoms and the two-dimensional material matrix. Cobalt atom intercalation regulates the reaction kinetics of the catalyst, enhances the distribution of photogenerated carriers on the surface of the catalyst, and inhibits the recombination of photogenerated electrons and holes. This 2D material intercalation technique increases the catalyst‘s light absorption efficiency while also improving adsorption and desorption of reactants and gas products. Combined with DFT calculations, it is demonstrated that the confinement effect of cobalt atom intercalation introduces additional catalytic active centres and reduces the free energy of the reaction intermediate COOH*. As a result, under 420 nm visible light irradiation in the gas-solid reaction with low water vapor content without any promoters or sacrificial agents, Co-BiOBr achieve a CO formation rate of 36.7 μmol g⁻¹ h⁻¹, nine times that of the original BiOBr. This work provides guidance for the development of new and efficient photocatalysts.