2 Preparation And Photocatalytic Degradation Of Phenol Compound Oxide Surface Of The Porous Magnetic TiO

TiO2is a kind of photocatalytic materials with high efficiency, good stability, nosecondary pollution photocatalytic. However, because of problems of TiO2with largeband gap and light weight that is not conducive to recovery limit its development in thefurther. Thus, in view of the problems faced by TiO2, researchers mainly focused on twofield of modification of TiO2photocatalytic materials and load two aspects. In this paper,based on research of traditional three-component coating material Fe3O4/SiO2/TiO2thatcan be magnetically separated. Semiconductor compound formed between SiO2andTiO2is retained, porous SiO2can lead to the increasing of effective area of TiO2and thereducing of the magnetic shielding the problem by the middle layer. Thus, the surfaceporous Fe3O4/porous SiO2/TiO2composite oxide is prepared. This experiment takescharacterization methods by XRD, SEM, FT-IR, XPS, Uv-vis, N2adsorption-desorptionand VSM. to analyze the magnetic TiO2composite oxides with surface porous. Explorethe influence of crystal structure, morphology, pore structure and magnetic performanceof composite oxide in different preparation methods and process conditions. It wasimproved the degradation efficiency of phenol simulation waste water by theoptimization of the preparation methods and preparation process.First of all, the Fe3O4particle was prepared by hydrothermal method. Results showthat the preparation of Fe3O4particles with the rules spherical, its size was about300nm. And Fe3O4magnetic particle is super paramagnetic material, the saturationmagnetization intensity was66.92emu/g., porous SiO2layer was prepared by sol-geland hydrothermal method and formed Fe3O4/porous SiO2composite material. Resultsshow that porous SiO2layer was in the amorphous form; Fe3O4/porous SiO2compositeparticle size was around350-450nm, it presented the rules spherical; Fe3O4and porousSiO2had certain connection structure in form of Fe-O-Si bonds; Fe3O4/porous SiO2composite material prepared by hydrothermal had more excellent pore structurecharacteristics, the surface area was625m2/g, pore volume was0.60cm3/g, pore size of3.12nm; saturation magnetization of composite material coated by porous SiO2layerafter ofwas about7.89emu/g higher than Fe3O4/SiO2. Second, TiO2shell of Fe3O4/porous SiO2/TiO2composite oxide was prepared byesters precipitation and sol-gel method, respectively. Results show that the TiO2effective components of composite oxide could be prepared with anatase. With theincreasing of TBOT quantity, TiO2was gradually become a complete crystal shape. Itwas found that the structure of Fe3O4/porous SiO2/TiO2composite oxide lead increasingof phase transition temperature of TiO2; it presented the rules spherical, particle size ofTiO2composite oxide was about500-600nm; The magnetic TiO2composite oxideswith surface porous prepared by two methods were both mesoporous materials,Fe3O4/porous SiO2/TiO2composite oxide prepared by esters precipitation had moreexcellent pore structure characteristics, the surface area was453m2/g, pore volume was0.31cm3/g, pore size of2.86nm; TiO2composite oxides prepared by two methods hadstronger absorption under UV and visible light than P25, photo corresponding rangecould expand to750nm and the band gap was reduced to1.77eV; saturationmagnetization of Fe3O4/porous SiO2/TiO2composite oxide prepared by estersprecipitation was about2.39emu/g.Finally, with homemade phenol solution as simulate organic wastewater, evaluatedthe photocatalytic performance of Fe3O4/porous SiO2/TiO2composite oxides. Themagnetic TiO2composite oxide with surface porous was researched the effects of lightcatalytic degradation of phenol on preparation process conditions (such as the middlelayer preparation method, TiO2shell preparation method, the content of TiO2, heattreatment temperature, etc.) and reaction process conditions (such as, reaction systempH value, reaction time, catalyst usage and catalyst dosing quantity, etc.). Through aseries of comparison and optimization, Fe3O4/porous SiO2/TiO2composite oxides to thephenol degradation rate was up to87%, removal rate of COD was above73%.