Using ilmenite as a raw material, iron was converted into Fe3O4 magnetic fluid, which further was combined with titanium filtrate by a solvothermal method. Finally Fe3O4/TiO2 nanocomposites with the uniform size of 100–200 nm were prepared. This approach uses rich, inexpensive ilmenite as a titanium and iron source, which effectively reduces the production cost. The crystal structure, chemical properties and morphologies of the products were characterized by SEM, TEM, XRD, FTIR, BET, UV-Vis, XPS and VSM. The novel photocatalyst composed of face-centered cubic Fe3O4 and body-centered tetragonal anatase–TiO2 exhibits a spherical shape with porous structures, superparamagnetic behavior and strong absorption in the visible light range. Using the degradation reaction of Rhodamine B (RhB) to evaluate the photocatalytic performance, the results suggest that Fe3O4/TiO2 nanocomposites exhibit excellent photocatalytic activities and stability under visible light and solar light. Moreover, the magnetic titania nanocomposites displayed good magnetic response and were recoverable over several cycles. Based on the trapping experiments, the main active species in the photocatalytic reaction were confirmed and the possible photocatalytic mechanism of RhB with magnetic titania was proposed. The enhanced photocatalytic activity and stability, combined with excellent magnetic recoverability, make the prepared nanocomposite a potential candidate in wastewater purification.
Bismuth vanadate (BiVO 4 ) hollow spheres with porous structure have been successfully fabricated by a onestep wet solution method with no surfactant and template. The structure, morphologies, and composition of the as-prepared products were studied with X-ray powder diffraction (XRD), transmission electron morphology (TEM), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. Based upon the time-dependent experimental results, BiVO 4 nanospheres with hollow and solid structures can be controlled effectively through the reaction time, and a reasonable formation process was suggested in this work. Moreover, the experiment of degrading methyl orange (MO) under visible-light illumination was conducted to evaluate the photocatalytic performance of the obtained BiVO 4 samples. The porous BiVO 4 hollow spheres exhibit superior visible-light photocatalytic properties for MO degradation than other photocatalysts under irradiation, and could be reused for up to five times without significant reduction in the photocatalytic activity. In addition, based on active group trapping experiments, cOH radicals as the main active species from H 2 O 2 molecules play a vital role in the photocatalytic degradation of MO, and a photocatalytic mechanism for the BiVO 4 system was proposed. High photocatalytic activity, universality and stability suggest that the porous BiVO 4 hollow spheres may have potential applications in wastewater treatment. † Electronic supplementary information (ESI) available: (1) SEM images of BiVO 4 hollow spheres; (2) XPS spectra; (3) SEM images of BiVO 4 solid spheres; (4) XRD patterns; (5) effect of H 2 O 2 amount on photocatalytic degradation rate of MO in the presence of BiVO 4 hollow spheres; (6) PL spectra. SeeFig. 5 (a) Absorption spectra of MO aqueous solutions in the presence of BiVO 4 hollow spheres, (b) degradation rate of MO at different intervals and (c) pseudo-first-order kinetic plots of MO in the presence of various photocatalysts.This journal is
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.