Effect of carbon coating of TiO2/Fe3O4 particles on their photocatalytic activity

Magnetic titanium dioxide particles were prepared by depositing different amounts of TiO2 on magnetite powder using a sol-gel process. Adsorptivity of TiO2/Fe3O4 particles was increased by carbon coating which was carried out by mixing the particles with poly ( vinyl alcohol) as a source of carbon. The carbon coating and calcination of particles were carried out simultaneously by heating the mixture at different temperatures. X-ray diffraction, energy dispersion fluorescence x-ray spectrometry, carbon-nitrogen analyzer and surface area analysis were used for the characterization of the prepared samples. The phase transition temperature of TiO2 from anatase to rutile was found to decrease by decreasing titanium tetraisopropoxide to magnetite (TTIP: Fe3O4) ratio while BET surface area increased by increasing this ratio. Carbon content had a significant effect on the formed phases and surface areas of the samples. The photocatalytic efficiencies of the prepared samples were investigated against degradation of methyl orange. The effect of TTIP: Fe3O4 ratio and carbon content on the degradation rate were studied. Methyl orange degradation rate increased with the increase in TTIP: Fe3O4 ratio but decreased by increasing carbon content.