| Nanoscale TiO2photocatalysis has attracted intensive attention in water and wastewatertreatment to eliminate toxic and recalcitrant organic compounds because it is nontoxic,relatively cheap, chemically stable within a wide pH range, and robust under UV lightirradiation. However, the disadvantages of nanocrystalline TiO2are also conspicuous: fastrecombination of photogenerated electrons and holes and difficult to recycle. In this work, Akind of catalysts with high photocatalytic activity and magnetic separation characters wereprepared. The magnetic properties of Nickel ferrites and the adsorption features ofmesoporous carbon were combined in a composite by impregnation method to producemagnetic mesoporous carbon (MMC). This composite could be used as adsorbent forcontaminants in aqueous system and subsequently removed from the water by a simplemagnetic procedure.Then, TiO2was loaded by immersing MMC in titanium tetrabutylatesolution and then added a mixed solution of ethanol, water and hydrochloric acid understirring conditions. Stop stirring when TiO2sol appeared.24hours later, calcined it innitrogen atmosphere at480℃for2hours. The product particles were washed with deionizedwater for several cycles and recycled by magnetic separation, then a new magnetic compositephotocatalyst (TiO2/MMC) was obtained by the sol-gel method. The as-synthesized sampleswere characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM),nitrogen adsorption and vibrating sample magnetometer (VSM). Results show that theTiO2/MMC-30%magnetic photocatalyst composites contain NiFe2O4and anatase TiO2contents, grain size of0.15~0.2μm, specific surface area of138m2/g and saturationmagnetization of5.611emu/g. The results of degradation reaction of rhodamine B indicatedthat TiO2/MMC-30%magnetic composite photocatalyst had higher dark adsorptive capabilityas well as photocatalytic activity. The adsorption rate can attain to33.168%within30min, andthe degradation rate can reach100%within3.5h under the irradiation of an8w low pressuremercury lamp. It can be seen that TiO2/MMC has both good magnetic properties andphotocatalytic activity. |
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