Strong Absorption Water Treatment Of Sun Light Catalyst Modification Research

With the development of science and economy, more and more pollutants are produced byhuman activity. There are still some organic pollutants hard to be degradation bymicro-organisms, and can do great harm to environment. Photocatalysis technology has beenused in the research of the degration of persistent organic pollutants in atmosphere and water,and the research has made the remarkable result. Photocatalysts have characteristics of wideantimicrobial spectrum, deodorising, cleansing and air freshening, they have broad prospectsin environmental protection. The main photocatalysts be researched are nano TiO2, ZnO andCdS, but there are many problems for actual application, such as low catalytic efficiency andlow utilization of daylight.The preparation of nano ZnO was described in this paper, and modified nano Cu/ZnO andZnO@C were prepared with anhydrous cupric sulfate and glucose as modifiers. Then thecatalytic properties and adsorption capacity of three catalysts were compared with methyleneblue trihydrate as model pollutant. And the influence of different lights to the degradation ofMB solution were compared in the paper. The present study might provide some theoreticaland technology proofs for the preparation of more practical and cost-effective catalysts.The main contents and results are following:Nano ZnO sticks are prepared by solvothermal reaction and hydrolyze method, with zincacetate, NaOH and anhydrous ethyl alcohol as raw materials. The average length of nano-ZnOsticks is 700~800 nm, and the average diameter range is 40~50 nm. The nano-ZnO sticksdisperse well, there is no combination phenomenon. Photocatalytic degradation experiment isproceeded with MB as model pollutant. The initial concentration of MB solution is 10 mg/L,photocatalyst is 1g/L. The concentration of MB solution change little after one hour’s absorptionexperiment, that is to say the nano-ZnO sticks have small sorption capacity. The MB solution hasbeen degraded 99.4% under 150 min imitate daylight, and 78.1% under 180min imitate visiblelight. The nano-ZnO sticks have good photocatalytic property under both two lights.Anhydrous cupric sulfate is be used as raw material to modify nano-ZnO sticks. The massratio of Cu and ZnO is set to 1%, 3%, 5%, 7%, 10%. The average length of the Cu/ZnO productsis 1 cm, and the average diameter range is 50~60 nm. The diameter of Cu nanoparticle is about40~60nm. Photocatalytic degradation experiment is proceeded with MB as model pollutant. The initial concentration of MB solution is 10 mg/L, photocatalyst is 1g/L. The concentration of MBsolution change little after one hour’s absorption experiment, that is to say the Cu/ZnO materialshave small sorption capacity. The photocatalytic property of Cu/ZnO materials have nearly nodifference under both lights. Using 10% Cu/ZnO as photocatalyst, the concentration of MBsolution has been reduced to 2.648 mg/L under 180 min imitate visible light, and reduced to0.145mg/L under 120 min imitate daylight and 0.019mg/L under 150min imitate daylight.Glucose is be used as raw material to modify nano-ZnO sticks. The depth of carboncladding is about 20~30nm when use 0.4g ZnO and 0.7g glucose as reactant. The nano-ZnO@Csticks disperse well. Photocatalytic degradation experiment is proceeded with MB as modelpollutant. The initial concentration of MB solution is 30 mg/L, photocatalyst is 1g/L. Theconcentration of MB solution reduce to 19.412mg/L after one hour’s absorption experiment, thatis to say the ZnO@C material has good adsorbability. The concentration of MB solution hasbeen reduced to 2.715 mg/L under 180 min imitate daylight. The nano-ZnO@C material hasgood photocatalytic property under imitate daylight.After all, the adsorbability has little difference between nano-ZnO and 10%Cu/ZnO, butunder imitate daylight 10%Cu/ZnO has better photocatalytic property than nano-ZnO. TheZnO@C has better adsorbability but a little worse photocatalytic property than nano-ZnO. Thereare still many work to do to improve adsorbability and photocatalytic property of nano-ZnO, butthe present study provide some theoretical and technology proofs for the preparation of morepractical and cost-effective catalysts.