Preparation And Photocatalytic Properties Of The Hollow Titanium Dioxide Micropheres With Dominant {001}Facets

Titanium dioxide is a very broad application of inorganic materials. As a photocatalyst, it has a very significant ground effect used for degrading of the organic matter,pollution abatement and so on. It is also a focus of recent research.In this paper, the hollow titania dioxide microspheres with dominant {001}facets were prepared by a one-step hydrothermal method. Scanning electronmicroscopy(SEM), Transmission electron microscopy(TEM), X-ray diffraction(XRD)were used to characterize the structure and morphology of the prepared products. TheUV-visible diffuse reflectance test was used to test the band gap and N2adsorption-desorption isotherm tested the specific surface area. The SEM and TEM results showedthat the morphology of the prepared products were uniform and hollow microspherestructure, the microsphere size was2-4μm; XRD results showed that the products wereanatase phase and the peak intensity percentage content of {001} facets was25.5%, theband gap was3.23ev, the specific surface area was60.285m2/g.Methylene blue was used as the target product of photocatalytic degradation andresearched to study the photocatalytic properties of the hollow titanium dioxidemicrospheres. In this article, methylene blue’s degradation rate and reaction rate constantin the photocatalytic process were used to evaluate the photocatalytic performance. Theinfluence of the amount of hydrogen peroxide, hydrofluoric acid were studied on theproperties of the photo catalyst and the influence of the concentration of NaOH, the initialconcentration of the degradation and the photo catalyst concentration on photocatalyticproperties. the photocatalytic experiments showed in the20min, the degradation ratereached80.97%, the photocatalytic reaction accord to a kinetic characteristic and thereaction rate K was0.08337/min. When the concentration of NaOH, the initialconcentration of the degradation products, the photo catalyst concentration in thedegradation solution were0.025mol/L,10ppm,80mg/200ml, the photocatalyticproperties reached the best. And it was found out that when the amount of the titaniumpowder, hydrofluoric acid, hydrogen peroxide, deionized water in preparing titanium dioxide were60mg,0.35ml,9.0ml,21ml, the hollow titanium dioxide microsphereshad the best structure, morphology and highest catalytic efficiency.The silver doping research was based on these, the XRD results showed theappropriate amount of silver doping did not change the crystal structure of titaniumdioxide, the percentage of {001} facets had been improved from25.5%to32.8%. Thephotocatalytic results showed the catalytic efficiency added obviously after silver dopingand arrived at the best with doping amount of2.0%. After the BET test, the specificsurface area of the samples had increased from60.285m2/g to74.394m2/g after doping.By calculating the band gap of the products, it was found that the band gap reduced alittle from3.23ev to3.13ev and the absorption of visible light region became larger afterdoping, and the catalytic efficiency improved quickly.