Flower-like CoAl layered double hydroxides modified with CeO2 and RGO as efficient photocatalyst towards CO2 reduction

In this article, a simple yet effective in situ hydrothermal method has been developed to synthesize a series of CeO 2 and reduced graphene oxide (RGO) stepwise-doped CoAl-LDH (CACR) composites with CoAl-LDH/CeO 2 (CAC) as the intermediate. The smart design well integrates the photo-electrochemical merits of CoAl-LDHs and CeO 2 with conductive RGO to form an optimized formula with high light-harvesting ability, efficient charge separation, and rapid electron transfer . Owing to these features, the sample of CAC-5-R-10 containing 5 wt% CeO 2 and 10 wt% RGO, is found to be the most efficient one as the catalyst for CO 2 photoreduction with a high average CO evolution rate of 5.5 μmol·g −1 ·h −1 at 25 °C without sacrifice reagent or extra photosensitizer under ultraviolet light, which surpasses those of the single CeO 2 , CoAl-LDHs, the intermediate of CAC, and many reported LDH-based counterparts. With the assistance of Mott–Schottky curves, the Z-scheme mechanism is proposed for the significantly enhanced photo-activity of the CAC-5-R-10. The present work provides a good sample for integrating LDHs with a second semiconductor and conductive RGO for collaborative optimization of photoelectric characteristics towards enhanced CO 2 photoreduction.