| At the present day,photocatalysis technology has been getting more and more attention among various sewage treatment techniques,and its application prospects are also very broad.The photocatalysis technology can take full advantage of energy from almost infinite and green sunlight or other artificial light source to degrade organic pollutant in the sewage.Unlike traditional transfer of pollutants,photocatalysis technology is able to break pollutants down into inorganic molecules and ions more thoroughly,which depends on structure and property of the catalysts.Nano TiO2 becomes the best material in photocatalysis research because of its nice property,stabilization,nontoxicity and cheapness.However,the energy gap of TiO2 is so broad that it can only be stimulated by UV-light,which imposes great restrictions on its wide application.As a kind of organic semiconductor with graphite-like structure,g-C3N4 has great stabilization as well as a narrow energy gap,which makes it possible for g-C3N4 to degrade organic pollutants under visible light.By compositing TiO2 and g-C3N4,a composite nano material with narrow energy gap can come into being,and because of coupling between two materials,recombination of electron and hole was reduced so that photocatalytic performance of composite material was enhanced.And as a consequence,this page focuses on the following parts:(1)Fabrication and Photocatalytic Property Research of g-C3N4/TiO2 compositematerialg-C3N4/TiO2 composite nano material was fabricated by mixed calcination using metatitanic acid and melamine as raw material and so that researches could be conducted on effects of materials' proportion,calcination temperature,calcination time and heating rate to find the best fabrication conditions.Characterization of the composite materials was conducted by XRD,UV-Vis DRS,FT-IR,SEM and TEM.And as a result of photocatalytic experiments,the highest degradation rate of methylene blue in 3 hours was found to reach 99.64%under the circumstances of materials' proportion being 0.25,calcination temperature being 500? calcination time being 1.5h and heating rate being 10?/min.Besides,·O2-was found to be the key matter by mechanism experiments.(2)Effects of Reaction Conditions on g-C3N4/TiO2 Composite Nano Material's Photocatalytic Propertyg-C3N4/TiO2 composite nano material was used to degrade methylene blue under visible light to study effects on this reaction of different catalyst's concentration,substrate's concentration and pH while photocatalytic stabilization of the catalyst was determined by repetitive tests.And it can be found that,when catalyst's concentration was 0.5g/L,substrate's concentration was 20mg/L and pH was 6,we can get the highest degradation rate of methylene blue.Besides,the catalyst's stabilization was found to be very well after 4 round experiments.(3)Effects of Acidification of g-C3N4/TiO2 Composite Nano Material on Its Photocatalytic Propertyg-C3N4/TiO2 composite nano material was acidized by soaking in concentrated hydrochloric acid to study its photocatalytic property under visible light,and was characterized by XRD,UV-Vis DRS,FT-IR,SEM,TEM and PL,which told us that acidification of g-C3N4/TiO2 can enhance its photocatalytic property while make no difference to the material's structural feature. |
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