Hydrothermal synthesis of FeWO4-graphene composites and their photocatalytic activities under visible light

Monoclinic ferberite FeWO4-reduced graphene oxide (FeWO4-RGO) composites were hydrothermally fabricated by facile one-pot method in situ reduction of graphene oxide. As-prepared FeWO4-RGO photocatalysts were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectra, and diffuse reflectance spectra (DRS). The FeWO4-RGO photocatalysts and pure FeWO4 photocatalyst had a similar particle size, which was in the range of 30-50 nm. FeWO4 and FeWO4-RGO photocatalysts showed absorption in the visible region, and the band gap energy of FeWO4 decreased slightly after RGO coupling. FeWO4-RGO photocatalysts exhibited high efficiencies in photocatalytic degradation of dye pollutant Rhodamine B (RhB) in solution under visible light irradiation (a 4W Light Emitting Diode lamp). All FeWO4-RGO photocatalysts under visible light showed higher photocatalytic activities than pure FeWO4 photocatalyst, and FeWO4-0.3RGO showed the best photocatalytic activity. The FeWO4-RGO composites were formed through the chemical contact between nanometer FeWO4 particles and RGO, and RGO could act as a good electron acceptor. The enhancement in visible-light photocatalytic performance may be mainly attributed to the effective separation of the photogenerated electron-hole pairs. (C) 2015 Elsevier B.V. All rights reserved.