Preparation and characterization of novel alkylviologens-intercalated vanadyl-vanadate (RV)V3O8

Various n-alkylviologens-intercalated vanadyl-vanadate (RV)V3O8 were synthesized with the combination of redox and ions-exchange methods. The derivative compounds were characterized by X-ray diffraction (XRD), FT infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). The XRD results indicate that the interlayer spacing increases with the alkyl chain length of the alkylviologen cations. The FTIR data shows that alkylviologens were inserted into the interlayers of V3O82−. XPS data reveals that the vanadium ions in the intercalation compounds are mostly in a pentavalent V5+ state with some partially reduced to the V4+ state. The intercalation compounds have the strong absorption character in the ultraviolet and visible light region. Magnetic susceptibility indicates that the (ethylviologen) V3O8 (EV3) is antiferromagnetic and possesses an ordered magnetic structure below 15 K. Above 15 K, EV3 exhibits paramagnetic behavior and a disordered magnetic structure.

The (001) reflection of the intercalation compounds shifting to a lower 2θ value in comparison with that of (NH4)2V3O8 implies the interlayer space was undergone expansion after intercalation.Figure optionsDownload as PowerPoint slideHighlights
► Novel alkylviologens-intercalated vanadyl-vanadate (RV)V3O8 were synthesized.
► Layered framework of V3O8 was still maintained after alkylviologens intercalation.
► The vanadium ions of intercalation compounds are composed of V5+ and V4+ cations.
► Theses compounds have strong absorption in the ultraviolet and visible light region.