Visible light-driven photocatalyst: An iron(III) coordination compound in Rhodamine B degradation

Abstract

Rhodamine B (RhB) was photocatalytically degraded by an iron(III) complex (FeL3, L = Methyl 3-hydroxy-2-propenedithioate). The photocatalysts were synthesized, supported on glass slides, and characterized by elemental analyses, IR, UV–vis, Raman, TGA, XPS, Diffuse Reflectance spectroscopy, and Powder X-ray diffraction analyses. The iron complex was also impregnated onto titania (TiO2) films to enhance the photocatalytic performance of this oxide. The structure of the complex does not change when supported on a glass substrate. The FeL3 showed a band gap value (Eg = 1.32 eV) lower than TiO2 (Eg = 3.38 eV), whereas the FeL3 sensitized titania showed the highest Eg value (Eg = 3.41 eV). The photocatalytic degradation of RhB by the TiO2-FeL3 system (27%) after 180 min of reaction slightly improves the performance of TiO2 (22%). Remarkably, FeL3 film showed the best performance (34%). When using scavengers, the degradation reveals that the produced superoxide radicals seem to be responsible for the RhB degradation.