Atomic intercalation - an approach to enhance photogenerated carrier dynamics for efficient photocatalysis carbon dioxide reduction.

Visible-light-driven CO2 reduction presents a long-term answer to environmental challenges. 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 atomic 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 cobalt atom intercalation introduces additional catalytic active centres, and reduces the free energy of the reaction intermediate COOH*. As a result, under 420nm 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 which without cobalt atom intercalation under the same condition.