Preparation And Photo-catalytic Performance Research Of Cerium-doped TiO₂Nanotubes

With the increasing of global energy crisis and environmental pollution, energyand environmental issues have aroused increasing attention, the development of highefficiency, low power consumption, wide application and environment-friendly newfunctional materials become to the urgent need to address problems. With furtherresearch, it was found that the photo-catalytic semiconductor technology is a newenvironmentally friendly technology that low energy consumption, easy operation,mild reaction conditions, a wide range of application, little secondary pollution. Inmany semiconductor photo-catalysts, due to higher photo-catalytic efficiency,chemical stability, low cost, non-toxic, etc. TiO2has become a hot research material indomestic and international environment. However, titanium oxide as a photo-catalyst,there are some drawbacks, for example: a wide band gap (Eg=3.2eV), large energyis required for the absorption of ultraviolet light, Sunlight utilization rate is very low.For the above shortcomings, in this paper, we prepared un-doped and cerium-dopedtitanium dioxide nanotubes, and researched the effect of photo-catalytic properties ofdifferent factors on them. The main studying were as follows:1. Taken tetrabutyl titanate as the titanium source, cerium nitrate as the ceriumsource, used the sol-gel method combined hydrothermal to synthesis un-doped andcerium-doped titania nanotubes photo-catalyst. Based on the rate of degradation ofmethylene blue, we researched the effects of preparation process precursor ratio,calcinations temperature, calcinations time, and cerium doped photo-catalyticefficiency of the sample. The results showed that when the precursor ratio n=Ti(OC4H9)4: C2H5OH: HNO3: H2O=1:15:0.7:2, calcinations temperature was450℃,calcinations time was3h, cerium doped W (Ce3+/TiO2)=1.5%, the sample has thehighest photo-catalytic efficiency. 2. Determined the optical lattice structure and phase composition of the catalyst byX-ray diffraction, measure the morphology by transmission electron microscopy(TEM) and elemental analysis by EDS, internal visible infrared spectroscopy analysisof samples visible spectrophotometer sample absorbance-bond structure with UV.XRD results showed that the sample calcined at450℃was anatase, exceeds500℃,anatase and rutile phase coexistence. Diffraction peak of Cerium oxide does notappear, and the diffraction intensity of doped samples is better than the un-doped.Cerium doped is conducive to the crystallization of titanium dioxide. TEM resultsshowed that the samples are nanotube structure, diameter of about10nm, dopedsamples have significantly larger tube length than the un-doped. EDS analysis showedthat cerium ions certainly doped into the titania lattice.3. Taken a series of photo-catalytic experiments on the resulting sample.Researched the effects on photo-catalytic efficiency of the amount of photo-catalyst,initial concentration of degradation material and the photo-catalytic time. The resultsshowed that under optimum conditions, when the amount of catalyst was20mg/25ml,the initial concentration of methylene blue was20mg/L, the photo-catalytic reactiontime was2h, the doped sample has the highest photo-catalytic degradation efficiencyreached97.4%, improved16.1%compared with the un-doped sample.