Synthesis of iron phthalocyanine/CeO2 Z-scheme nanocomposites as efficient photocatalysts for degradation of 2,4-dichlorophenol

Abstract

Modulating the photogenerated electrons of CeO₂ to activate O₂ and efficiently photocatalytic degradation of chlorophenols is a highly desired goal. Herein, we have successfully fabricated an FePc/CeO₂ heterojunction through H-bond induced assembly. The photocatalytic degradation of 2,4-DCP by the amount-optimized FePc/CeO₂ nanocomposite was improved by 3 times compared with that by pure CeO₂. By means of electron paramagnetic resonance (EPR) and single wavelength photocurrent spectroscopy, it is confirmed that the excellent photocatalytic performance is mainly attributed to the formation of the Z-scheme heterojunction, which promotes charge separation and transfer, and the introduction of FePc broadens the visible light absorption range of the heterojunction. Moreover, O₂ temperature-programmed-desorbed curves and electrochemical O₂ reduction measurement results demonstrate that the single Fe–N₄(II) site in FePc is more conducive to promoting O₂ activation than that of other metal phthalocyanines. Based on in situ FT-IR and liquid chromatography–tandem mass spectrometry (LC-MS/MS), a possible reaction pathway of 2,4-DCP degradation was proposed. This study provides a novel strategy for preparing CeO₂ based Z-scheme heterojunctions with abundant monoatomic sites for pollutant degradation.