Cerium Metal–Organic Framework Incorporating Quinoline Sulfonic Acid for Photocatalytic Carbon Dioxide Reduction

Cerium metal–organic frameworks (Ce-MOFs) have attracted extensive attention due to their potential in photocatalytic applications. However, Ce-MOFs constructed with organic carboxylic acids as ligands typically exhibit wide band gaps, which limit their utilization in the visible-light region. This work proposes a strategy to design visible-light-active Ce-MOFs by employing quinoline sulfonic acid as a ligand. The synthesized compound (1-Ce) features a high surface area, open Ce metal sites, and large-sized 1D channels. Benefiting from ligand-to-metal charge transfer, 1-Ce demonstrates good visible light absorption. Additionally, the chelating coordination of nitrogen and oxygen atoms endows 1-Ce with excellent chemical stability. Owing to its abundant metal sites, high porosity, and visible light responsiveness, 1-Ce exhibits outstanding photocatalytic activity for CO2 reduction under visible light, achieving a CO production rate of 138 μmol·g–1·h–1─surpassing previously reported Ce-MOF photocatalysts.