Generation of Lattice Strain in CdS Promotes Photocatalytic Reduction of CO2

The key to photocatalysis lies in the efficient separation and migration of photogenerated carriers to the surface for participation in the reaction. However, the recombination of electrons and holes is a major hindrance that reduces the photocatalysis activity. Herein, we developed a method to introduce lattice strain by regulating the crystallinity of the material, thus resulting in an intensive polarization internal electric field, which can promote the separation process of electrons and holes and improve the efficiency of photocatalysis. The degree of strain can be controlled by the solvothermal temperature. Compared with CdS-160 °C, CdS-100 °C with a larger lattice strain degree and internal electric field contributed to a 7-fold enhanced photocatalytic CO evolution from CO2; in addition, the CO/H2 ratio was also increased by 4 times. This study reports the important effects of lattice strain and internal electric field on photogenerated carrier separation and migration, providing valuable insights for designing efficient photocatalysts.