Photocatalytic Properties Of Composite Materials

Harmful organic pollutants can be completely decomposed into harmless inorganicsmall molecules used photocatalytic oxidation technology,and the energy conservationand environment protection.Nanometer TiO2can fully degrade various of organic pollutants and is widely studied,but the single TiO2powders adsorption ability is week,useeasy to loss,which limits its practical application.So the photocatalytic composite material that TiO2can be loaded strong has the practical and long-term significance.In this paper,self-madeTiO2powder was characterized by EDS,TEM,,XRD,UV-Vis.Choosing appropriate carrier between poly and perhafnate made the photocatalytic composite material,and the best carrier was characterized by TEM.The photocatalytic performance was explored by using methyl orange pigment solution as substrate,the preparation conditions,such as material ratios,light conditions,pollutant initial concentration,pH value,were optimized.The degradation effects of the composite photocatalyst on commonfood pigments,such as carmine,sunset yellow and lemon yellow,were studied under theoptimum conditions.The cleaning effects of the indoor air were studied by using formaldehyde,the conditions,such as material ratios,adsorption, light conditions,membrane surface area,were optimized. The degradation effects of benzene were studied under the optimum conditions.The determination of the bacterial resistance of the composite material was studied.The results are as follows:(1)The self-made modified nanoTiO2characterization indicates that contained N and S elements,had good dispersion,rod-shaped morphology,had anatase and rutile type two kinds of crystal.perhafnate was the better carrier,and maintaining1d,the effect wasbest.TEM characterization of the composites showed that nanaTiO2bare outside the perhafnate,did not affect its photocatalytic performance.(2)The degradation efficiency of methyl orange was excellent when perhafnate and nano-TiO2was compounded film according to8:2;The lower the initial concentration, photocatalytic effect is better;Adsorption promoted the photocatalytic degradation,After120min, the absorption peak disappeared at maximum absorption wave-length of464nm, and characteristic peak at270nm was also gone, which showed that methyl orange degradation occurred completely; Elimination of methyl orange was higher when pH values of the solution was between6and8. Degradation rate of ponceau4r,sunset yellow, tartrazine reached respectively88.1%、95.6%、97.1%after120min.(3)The degradation efficiency of formaldehyde was excellent when perhafnate andnanoTiO2was compounded film according to7:3;Adsorption promoted the photocatalytic degradation.Composite membrane surface area was1/3reactor surface area,high degradation efficiency of formaldehyde and the economy.Under the optimal conditions,after24h, benzene concentration by0.91mg/m3degradation to0.14mg/m3,the degradation rate reached85%.(4)The composite antibacterial rate of the total number of bacteria reached99.11%.the resistance of different bacteria rate as follows:E coli bacteria was grater than99.99%,Staphylococcus aureus was99.99%,Klebsiella pneumonia was99.99%,Pseudomonasaeruginosa was99.99%.A composite photocatalytic material was prepared by using self-made as mainbody and perhafnate as support. The composite photocatalytic material had strong caking property and simply forming process of composite, perhafnate adsorbed the pollutants to the surface of nanoTiO2,which resulted in direct contact with nanoTiO2and pollutants,improving the photocatalytic degradation performance of the nanoTiO2.The composite photocatalytic material is a kind of material with extensive practical value.