Constructing CoAl-LDO/MoO3_x S-scheme heterojunctions for enhanced photocatalytic CO2 reduction

Converting CO2 into chemicals and fuels by solar energy can alleviate global warming and solve the energy crisis. In this work, CoAl-LDO/MoO3_x (LDO/MO) composites were successfully prepared and achieved efficient CO2 reduction under visible light. The CoAl-layered double oxides (CoAl-LDO) evolved from CoAl-layered double hydroxide (CoAl-LDH) exhibited a more robust structure, broader light absorption, and improved CO2 adsorption ability. The local surface plasmon resonance (LSPR) effect excited by nonstoichiometric MoO3_x broadened the photo-response range of CoAl-LDO/MoO3_x. In addition, constructing step-scheme (S-scheme) heterojunctions could simultaneously optimize the migration mechanism of photogenerated electrons and holes, and retain carriers with strong redox ability. Therefore, the production rates of CO and CH4 on the optimal LDO/MO composite were 7 and 9 times higher than the pristine CoAl-LDH, respectively. This work hybridizes oxidation photocatalysts and LDO-based materials to optimize the charge separation and migration mechanisms, which guides the modification of LDO-based materials.

Automated summary

Converting CO2 into chemicals and fuels by solar energy can alleviate global warming and solve the energy crisis. This study successfully prepared CoAl-LDO/MoO3_x composite and achieved efficient CO2 reduction under visible light. The use of nonstoichiometric MoO3_x and the construction of step-scheme heterojunctions improved the photo-response range and optimized the charge separation and migration mechanisms, resulting in significantly increased production rates of CO and CH4.