Fabrication of Er3+/Yb3+ co-doped NiAl-LDH with promoted photocatalytic performance for CO2 reduction under Vis/NIR light irradiation

In this study, Er3+/Yb3+ co-doped NiAl-LDH (LDH:Er3+,Yb3+) photocatalysts were successfully fabricated through a solvothermal process. The results revealed that the LDH:Er3+,Yb3+ displayed promoted photoreduction CO2 activity under Vis/NIR light irradiation. A maximum CO yield of 13.2 μmolg−1h−1 had been obtained on LDH:1%Er,2%Yb, which was 9.4 and 1.5 times higher as high as the pure LDH and the LDH:1%Er, respectively. The improved photocatalytic activity can be ascribed to the expanded photoresponse range to NIR light region caused by the upconversion effect of Er3+/Yb3+, and the improved photogenerated charge separation efficiency with Er3+/Yb3+ serving as an electron trap. The NIR photocatalytic activity and the improved light absorption of LDH: Er3+,Yb3+ indicate that the upconversion mechanism is involved in the whole photocatalytic process. Therefore, this result presents new insights for the rational construction of Vis-NIR light-driven photocatalysts with high-efficient solar energy utilization and practical application prospects in the future.