Facile Preparation of Unsubstituted Iron(II) Phthalocyanine/Carbon Nitride Nanocomposites: A Multipurpose Catalyst with Reciprocally Enhanced Photo/Electrocatalytic Activity

The development of new catalytic materials is conducive to solving the global energy crisis and environmental problems. In this work, multipurpose catalyst unsubstituted iron(II) phthalocyanine/carbon nitride nanosheet (FePc/CN) nanocomposites were prepared by utilizing concentrated sulfuric acid as an ideal solvent of CN and unsubstituted FePc. Such FePc/CN nanocomposites exhibited improved photo/electrocatalytic activity which was enhanced reciprocally: the photocatalytic activity of CN was promoted by FePc anchoring, and the electrocatalytic activity of FePc was improved by CN doping. The photocatalytic performance of FePc/CN–0.3 nanocomposites was about 6.4 and 1.7 times as high as FePc and CN, which was attributed to two reasons: (1) the anchoring FePc on CN extended the visible-light absorption region of CN, (2) the electron transfer from excited FePc to CN hindered charge carriers recombination and thus enhanced the photoinduced carrier separation efficiency. Relative to FePc and CN, the onset potential of FePc/CN–0.3 was positively shifted by 52 and 174 mV, such higher oxygen reduction reaction activity was due to the uniform dispersion of FePc on the supporting material CN without aggregation, which led to improved conductivity and stability of nanocomposites. This approach will contribute to an inexpensive and convenient synthetic strategy of transitionmetal-based nanostructures for functional applications in photovoltaic, electrochemical, and catalytic fields.