Photocatalytic Reduction of CO₂ with H₂O Mediated by Ce-Tailored Bismuth Oxybromide Surface Frustrated Lewis Pairs

Abstract

Photocatalytic reduction of CO2 into available organic compounds has received remarkable attention. However, photocatalytic CO2 reduction is limited to meet industrial application requirements because of the lack of effective photocatalysts. Surface frustrated Lewis pairs (FLP) are found in bismuth oxybromide (BiOBr), which are effective catalytic sites to activate and photocatalytically reduce CO2. Furthermore, the introduction of Ce4+ and oxygen vacancy can optimize both the electronic state and the FLP property of BiOBr. The combined experimental and theoretical characterizations reveal that Ce4+ and O2– can form the frustrated Lewis acid–base pairs, which can catch, excite, and reduce CO2 into CO at a high yield of 50.9 μL h–1, being 9.8 times as large as pristine BiOBr. This work illustrates a rational strategy for both construction of highly efficient photocatalysts and insights into the photocatalytic mechanism at the atomic level.