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ygb123456(金币+15, 翻译EPI+1): 2010-05-06 16:14:43
During the photocatalytic reaction,remove 5 ~ 7 mL solutionat from the reactor at regular intervals.Then measured the absorbance of methylene blue by UV at 664nm after centrifugation.Figure 4-7 is the map of photocatalytic degradation of samples to methylene blue.From figure 4-7,we know that photocatalytic degradation rate is increased with the increase of the reaction time.When sunlight is only 20 mins,the degradation rate of methylene blue is up to 86.68%.This shows that Sb2S3 has a high efficiency of photocatalytic degradation to methylene blue in the sunlight,giving a high visible light photocatalytic activity.From the samples' UV-visible spectra,the absorption peak area of Sb2S3 is between 730 to 780nm which is in the visible range.After calculating,we know that the band gap is 1.53 eV.As a result,Sb2S3 can adsorbe the sunlight in the visible light and producing hole - electron pairs through irradiating by sunlight.By adsorpting the oxygen in the surface of the catalyst Sb2S3 trappes electron and produce •O2.In the same time,the hole oxidizes OH-and H2 O which adsorbe on the surface of the catalyst Sb2S3 into HO•.The atomic oxygen and hydroxyl radicals of the hole with a strong chemical activity has a strong oxidation[88].It can degradate methylene blue by photocatalysis effectively.希望有用 |
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