Construction of α-Fe₂O₃/Sulfur-Doped Polyimide Direct Z-Scheme Photocatalyst with Enhanced Solar Light Photocatalytic...

A novel two-dimensional α-Fe₂O₃/sulfur-doped polyimide (FO/SPI) direct Z-scheme photocatalyst was successfully constructed by a facile thermal treatment method. The effects of α-Fe₂O₃ nanosheets on the morphology, chemical structure, and photoelectronic properties of FO/SPI composites were systematically characterized by different spectroscopic means. These methods include X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, transient fluorescence spectra, and so forth. It was confirmed that the small amounts of α-Fe₂O₃ can availably facilitate exfoliation of bulk SPI, resulting in a transformation of SPI from bulk to 2D layered composite that illustrates tight interface through the coordination Fe-N bond and an all-solid-state direct Z-scheme junction. Thus, the transfer and separation efficiency of photogenerated electron/hole pairs were significantly enhanced, which greatly promoted improvement of the photocatalytic activity of the FO/SPI composite for methyl orange degradation under solar light. This work provides a new approach to constructing efficient inorganic-organic Z-scheme photocatalyst based on strong interface interaction.