FeWO4/g-C3N5 heterostructure for highly efficient visible-light-driven photocatalytic degradation of organic dyes

FeWO₄/g-C₃N₅ composites were prepared by a facile hydrothermal method. The composition and morphology of the catalysts were characterized by infrared spectroscopy (IR), X-ray powder diffraction (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS). The composition of FeWO₄ and g-C₃N₅ successfully reduces the band gap of g-C₃N₅ and broadens visible light response range. Moreover, the as-prepared FeWO₄/g-C₃N₅ composites inhibit the recombination of photoinduced carriers and improve the charge mobility. FeWO₄/g-C₃N₅ composites exhibit significantly enhanced photocatalytic activity for the degradation of organic dyes including methylene blue (MB), rhodamine B (RhB), and methyl orange (MO) under visible light irradiation. As for the MB degradation, the best degradation kinetic rate constant of FeWO₄/g-C₃N₅ composite is 3.6 times higher than that of pristine g-C₃N₅. Moreover, FeWO₄/g-C₃N₅ composite shows good photostability and reusability after cycling experiments, which may be used for the treatment of real wastewater. A Z-scheme mechanism of dye photodegradation by FeWO₄/g-C₃N₅ composite was also proposed based on the trapping experiment of the responsible radical species.