Ag-O-Ce³⁺ atomic interface and surface oxygen vacancies on CeO₂ synergistically promoted the selective visible photocatalytic reduction of carbon dioxide

The CO2 conversion into high-value-added chemicals is highly meaningful. Photocatalysis is a feasible and promising method to realize this transformation, in which photocatalyst plays a key role. Ceria (CeO2) has attracted extensive attention in the photocatalytic conversion of CO2. However, the surface oxygen vacancies (V(O)s) of CeO2 are unstable and lead to low reactivity. Herein, we found that the highly dispersed Ag species via coordination method stabilized the V(O)s of CeO2, and the synergy of the Ag species and V(O)s played a crucial role in the selective photocatalytic CO2 conversion. The formed Ag-O-Ce3+ atomic interface promoted the electron transfer from Ce3+ defective sites to Ag atoms, thereby improving the separation efficiency of the charge carriers, leading to enhanced photocatalytic activity. The V(O)s-sufficient CeO2 had high selectivity for the photocatalytic reduction of CO2 to methanol, while highly selective acetone was achieved on Ag- V(O)s/CeO2. The synergy of Ag and V(O)s that form a frustrated Lewis pair promoted not only the adsorption and activation of CO2 molecules but also the selectivity of products. The key intermediate species, *COOH and *CH3, were stably preserved by the synergy of Ag and V(O)s. This work provides insight into the selective conversion of CO2 to high-value-added organics via the surface regulation of photocatalysts.