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This study reports magnetic graphene oxide composite microspheres (MGO) were firstly synthesized via one step miniemulsion polymerization. α-FeOOH rods were then loaded onto MGO via a facile hydrothermal method to prepare α-FeOOH@MGO, which was served as the photocatalyst for the Fenton reaction. Subsequently, the properties of the resulting α-FeOOH@MGO were characterized by FT-IR, XRD, SEM, VSM and UV-vis DRS analysis methods. The influence of various parameters was investigated, such as dye type, dye concentration, H2O2 dosage, catalysts dosage and pH of MO solution during heterogeneous photo-Fenton processes. Under visible light irradiation, the degradation rate of MO, MB and CR could reach 99.96%, 98.47% and 99.97% in 40 min, respectively. Six cycle experiments confirmed that the α-FeOOH@MGO possessed a satisfied stability and recycling ability. In addition, the photocatalytic reaction mechanism was also revealed by the Mott-Schottky plot, band structure and trapping experiments of active species. [ABSTRACT FROM AUTHOR]

In this work, cobalt activated TiO2 photocatalyst have been successfully prepared on graphene oxide (GO) using simple and cost‐effective method to prepare Co‐TiO2/GO nanocomposites for the photocatalytic treatment of methylene blue (MB), representative organic dye, under visible light irradiation. The as‐prepared samples were characterized by X‐ray diffraction (XRD), High resolution transmission electron microscope (HRTEM), X‐ray photoelectron spectroscopy (XPS), UV‐vis diffused reflectance spectra (DRS), Raman spectroscopy and photoluminescence spectroscopy (PL). The characterization results confirmed that Co‐TiO2 catalyst is decorated on the graphene oxide. The photocatalytic efficiency of Co‐TiO2/GO for the degradation of MB was also improved by changing the proportion between Co‐TiO2 and GO. Highest photocatalytic activity was observed for Co‐TiO2 loaded with 5 wt % GO (88.7 %) compared with neat Co‐TiO2 (43.4 %) after 180 min of visible light irradiation. Furthermore, degradation by products was analyzed on Quadrupole Time‐of‐Flight Liquid Chromatography/Mass Spectroscopy (QTOF/LCMS) and the possible degradation pathway was proposed. It is investigated that the Co‐TiO2/GO nanocomposite has potential use in the catalytic degradation of organic contaminants under visible light irradiation. [ABSTRACT FROM AUTHOR]

A novel bismuth vanadate–silicon dioxide–graphene oxide (BiVO4/SiO2/GO) nanocomposite was synthesized successfully by using hydrothermal method. The as-prepared nanocomposite was characterized by various techniques, including X-ray diffraction (XRD), field emission scanning electron microscope (SEM), and Brunauer–Emmett–Teller (BET). The photocatalytic activity of nanoparticles was evaluated by measuring the removal efficiency of methylene blue (MB) in aqueous solution under visible light irradiation. The results indicated that BiVO4, BiVO4/SiO2, and BiVO4/SiO2/GO exhibited the same diffraction peaks of monoclinic scheelite structure due to the higher content of BiVO4 in the nanocomposite system. The BiVO4 and BiVO4/SiO2 were uniformly agglomerated from irregular particles with the different level of aggregation and the size of several micrometers. In the meantime, BiVO4 and SiO2 particles were adhered firmly on the GO sheets in BiVO4/SiO2/GO nanocomposite. The BiVO4/SiO2/GO nanocomposite showed a much higher efficiency than the pure BiVO4 and the BiVO4/SiO2 hybrid material for MB removal efficiency due to the considerably increased specific surface area and pore size by the adhesion of BiVO4 and SiO2 on GO sheets. [ABSTRACT FROM AUTHOR]