Visible-Light-Driven Photoreduction of CO2 to CH4 over N,O,P-Containing Covalent Organic Polymer Submicrospheres

Solar-energy-driven photoreduction of CO 2 to hydrocarbon fuels is an interesting and challenging topic, which generally requires photocatalysts with the capability to capture and photoreduce CO 2 simultaneously. Herein, we demonstrate that a N,O,P-containing covalent organic polymer (NOP-COP) prepared via condensation of hexachlorocyclotriphosphazene with barbituric acid can capture CO 2 and further photocatalyze its reduction to CH 4 under visible-light irradiation. The characterization information indicates that the incorporation of phosphorus in the skeleton of NOP-COP promoted the absorption of visible light and improved the lifetime of the photoinduced carriers. As a result, NOP-COP exhibited enhanced efficiency for photoreduction of CO 2 compared with the N,O-containing polymer, affording CH 4 as the sole carbonaceous product with a rate of 22.5 μmol g cat –1 h –1 and selectivity over 90%. This work provides insight into designing and fabricating polymeric photocatalysts for CO 2 photoreduction to fuels.