Preparation Magnetic Photocatalyst Of TiO₂/Fe₂O₃/CNTs For Photocatalytic Oxidation Reaction To Remove Terracycline Antibiotics From Aqueous Solutions

With research and development of antibiotics in the field of medicine, especiallytetracyclines as a broad-spectrum antibiotic have been widely used in treatment diseases ofhuman and animals. In addition, tetracyclines were used in the field of agriculture andbreeding industry, so that the residual of antibiotics in environment were accumulated moreand more. A lot of antibiotics industrial wastewater discharge in environment withoutdisposing, which will cause serious environmental pollutions. So, it’s more and moreimportant that how to deal with the antibiotic wastewater. TiO₂semiconductor photocatalyticoxidation is a new-style environmental pollution control technology, whose virtues are highlytreatment efficiency, simply equipment, easily operating condition, no toxicity and stabilitychemical property, etc. But owing to factors such as traditional TiO₂photocatalyst is difficultto separate for recycle, high operation cost and lowly light energy utilization rate, TiO₂semiconductor photocatalytic oxidation technology is limited to widely apply. In this paper,a new type of TiO₂photocatalyst are prepared that can easily separate and recycle，withhighly light energy utilization rate.Carbon nanotubes （CNTs） as the original support material, ferrite nanoparticles havebeen coated or attached onto carbon nanotubes, then magnetic carbon nanotubes （Fe₂O₃/CNTs）were obtained. After that, titanium dioxide were produced via sol-gel technology and calcinedat high temperature, TiO₂nanoparticles were coated to the magnetic material of Fe₂O₃/CNTs.Then composite magnetic photocatalyst of TiO₂/Fe₂O₃/CNTs were prepared successfully. Thenew type of photocatalyst （TiO₂/Fe₂O₃/CNTs） was characterized by X-ray diffractometer（XRD）, scanning electron microscope （SEM）, transmission electron microscope （TEM）,Vibrating sample magnetometer （VSM） and UV-VIS absorption spectra. The results show thatTiO₂/Fe₂O₃/CNTs have a good magnetism and light absorption spectra, which can takeadvantage of ultraviolet and most of visible light.Composite materials of TiO₂/Fe₂O₃/CNTs were used as the photocatalyst in experiment,tetracyclines （tetracycline hydrochloride， oxytetracycline hydrochloride, doxycyclinehyclate） as the target pollutants were removed by photocatalytic oxidation reaction.Experimental results show that the material of TiO₂/Fe₂O₃/CNTs can be used as aphotocatalyst under the visible-light, pollutants removal rate is up to85%-90%. Withoutcentrifuge only use external magnetic equipment to separate photocatalyst from solutions， Photocatalyst can be separated for recycle easily and efficiently, the average recovery was76.2%in ten times experments. After the photocatalytic catalytic reaction2-3times, therecovery photocatalyst is still has some ability of photocatalytic oxidation.