Controllable Synthesis, Photocatalytic Property, and Mechanism of a Novel POM-Based Direct Z-Scheme Nano-Heterojunction α-FeO/PMo.

In order to improve photocatalytic activity and maximize solar energy use, a new composite material FeO/PMo was prepared by combining polyoxometalates (PMo) with FeO nanosheets. FT-IR, XRD, XPS, SEM, TEM, UV-vis, EIS, and PL were used to characterize the composite material, and nano-FeO of different sizes and morphologies with a controllable absorption range was prepared by adjusting the reaction time, and, when combined with PMo, a composite photocatalyst with efficient visible light response and photocatalytic activity was constructed. The EIS, Bode, and PL spectra analysis results show that the FeOPMo composite material has outstanding interfacial charge transfer efficiency and potential photocatalytic application possibilities. Model reactions of methylene blue (MB) and Cr (VI) photodegradation were used to evaluate the redox activity of FeO/PMo composites under simulated visible light. The photocatalytic degradation rate was as high as 98.98% for MB and 96.86% for Cr (VI) when the composite ratio was FeO/PMo-5%. This research opens up a new avenue for the development of high-performance photocatalysts.