Enhanced photocatalytic CO2 reduction by integrating an iron based metal-organic framework and a photosensitizer

Abstract

The conversion of CO2 into fuels via photoreduction is a promising method to reduce environmental pollution and alleviate the energy crisis. Herein, we report iron-based metal-organic frameworks (Fe-MOFs) that can host a photosensitizer Ru(dcbpy)3Cl2 (PS) to form a range of photocatalytic systems, PS-Fe-MOFs, that are capable of increasing the activity of CO2 conversion. Among the four Fe-MOFs and PS composites, PSMIL-101(Fe) showed the highest activity for photocatalytic CO2 reduction under simulated visible light irradiation (yielding CO and CH4 at 116.7 and 79.1 μmol·g−1 within 5 h, respectively), approximately 13 times higher than that of pristine MIL-101(Fe). In situ FTIR spectra and theoretical calculations further elucidated the coexistence of CO and CH4 as the products of CO2 reduction by PSMIL-101(Fe). Additionally, the optical and electrochemical experiments, alongside theoretical calculations, indicated that PS bound on the surface of the Fe-MOFs provided a greater charge transfer efficiency, thus leading to a high photocatalytic CO2 reduction activity.