Implantation of Iron(III) in porphyrinic metal organic frameworks for highly improved photocatalytic performance

Herein a simple approach is proposed to greatly improve the photocatalytic performance of a porphyrinic metal organic framework (PCN-224) by implantation of coordinatively unsaturated Fe(III) sites into the porphyrin unit. Taking the photooxidation of isopropanol (IPA) as a model reaction, the newly developed Fe@PCN-224 exhibits significantly enhanced photocatalytic activity, which is equivalent to an 8.9-fold improvement in acetone evolution rate and 9.3-fold enhancements in CO2 generation rate compared with the PCN-224. Mechanism investigation reveals that the presence of Fe(III) sites in the PCN-224 can not only greatly boost the electron-hole separation efficiency, but also effectively convert the in-situ photogenerated inactive H2O2 into reactive oxygen-related radicals via Fenton reactions to participate in the photocatalytic IPA oxidation. The enhanced photocatalytic activity for IPA oxidation is also observed over another Fe(111) implanted porphyrinic metal organic framework (Fe@PCN-222), suggesting the generality of this strategy.