Defect-Induced Synergetic Effect of Bi-Based Compounds for One-Pot Conversion of Organic Pollutants into CO via Coupling Photodegradation of Carbamazepine with Photoreduction of CO2

The waste of carbon sources and greenhouse gas production during wastewater treatment have become extremely important environmental issues. Herein, the BiOBr/BiVO4 compounds with defect-induced frustrated Lewis acid-base pairs (DFLPs) and internal charge transfer were fabricated to convert the organic pollutants into CO with nearly 100% selectivity. The oxygen vacancy (O-v) induced the built-in electric field in BiOBr/BiVO4 to create directional charge transfer from BiOBr to BiVO4. Density functional theory (DFT) calculations prove that the O-v combines its adjacent hydroxyls to form the DFLP active sites that can additionally capture and activate CO2. Meanwhile, the active sites in BiOBr/BiVO4 reduce the formation-free energy of the COOH* intermediates, which is the key rate-limiting step to convert CO2 to CO with high selectivity. This system has achieved selective conversion of value-added chemicals from organic pollutant degradation and provides a theoretical basis for actual wastewater recycling of carbon sources.