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采用CTMAB/正丁醇/正庚烷/水四元反相胶束介质体系中直接沉淀法制备纳米CdS.采用不同ω([H2O]/[表面活性剂])条件制备的CdS光催化活性有所不同,当ω值为25时,所制备的纳米CdS光催化活性最高.利用X射线衍射仪(XRD)、透射电镜(TEM)对CdS的晶型、尺寸进行表征,结果显示,反相胶束法制备的CdS为立方闪锌矿型,ω值为25条件下制备的CdS平均粒径为9nm,且分散均匀.采用循环伏安法(CV)和电化学交流阻抗法(EIS)研究了纳米CdS的电化学行为,表明反相胶束法水量条件直接影响所制备的CdS粒径大小及电化学性质.在可见光照射下(λ≥420nm),光催化降解孔雀绿(Malachite Green,MG)为探针反应,探讨了不同反相胶束体系的制备条件对CdS光催化活性的影响,通过紫外-可见光谱(UV-Vis)和总有机碳仪(TOC)对光催化降解MG跟踪测定,表明可见光照射下以水量25制备的CdS中性条件下在70min内可以使MG褪色完全,反应30h后MG的矿化率达50%以上.同时跟踪测定了降解过程中H2O2和羟基自由基(-OH)的变化,表明CdS光催化机理涉及到-OH历程.
CdS nanocrystals were prepared by direct precipitation in a CTMAB / n-butanol / n-heptane / water reversed-phase micellar system.The photocatalytic activity of CdS prepared with different conditions of ω ([H2O] / [surfactant] , The photocatalytic activity of the prepared CdS nanocrystals was the highest when the value of ω was 25. The crystal form and size of CdS were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the reverse phase gel The CdS prepared by the beam method was of cubic sphalerite, and the average diameter of CdS prepared under the condition of 25 was 9nm, and dispersed uniformly. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) The electrochemical behavior of CdS nanocrystals showed that the water content of reverse micelles directly affected the particle size and electrochemical properties of prepared CdS.Macchite Green (MG) was photocatalytically degraded under visible light irradiation (λ≥420nm) For the probe reaction, the effects of preparation conditions on the photocatalytic activity of CdS were discussed. The photocatalytic degradation of MG was followed by UV-Vis and TOC. It shows that MG can be completely discolored within 70min under the condition of visible light irradiation under the CdS neutral condition prepared by water 25, After 30h reaction, the mineralization rate of MG reached more than 50% .At the same time, the change of H2O2 and hydroxyl radical (-OH) in the course of degradation was tracked, indicating that the mechanism of CdS photocatalysis involves-OH course.