纳米WO3/DWCNTs材料的制备及其光催化性能

Fabrication of WO3/DWCNTs composite photocatalyst with enhanced photocatalytic activity

摘要:

通过液相法制备出钨酸/DWCNTs和纯钨酸两种前驱体，尔后在氮气气氛下焙烧至700℃，保温2h分别生成了WO3/DWCNTs和WO3粉末。采用扫描电子显微镜和X射线衍射仪对产物的形貌和结构进行表征。在11W可见光的照射下，分别利用WO3/DWCNTs和WO3粉末对有机染料亚甲基蓝进行光催化降解反应，利用紫外-可见分光光度计测定出样品的紫外可见吸收光谱，通过朗伯比尔定律计算出光催化降解率。当光照时间为30 min时，WO3/DWCNTs降解率达到87.50 %，纯WO3降解率仅为25.39%。试验结果表明，DWCNTs的加入可以有效抑制颗粒的团聚，减小颗粒尺寸，增大WO3的比表面积，增强WO3的吸附能力，显著提高WO3对亚甲基蓝的光催化降解效率。

Abstract:

Two precursors, Tungstic acid/DWCNTs and pure tungstic acid, prepared by liquid phase method, were calcinated at 700 ℃for 2h at nitrogen atmosphere. Therefore, WO3/DWCNTs and WO3 powder were obtained respectively. The structure and morphology of as-synthesized products were characterized by powder X-ray diffraction (XRD) and Scanning electron microscope (SEM). The photocatalytic activity of the samples was evaluated by photocatalytic degradation of the methylene blue under visible light (11W) irridation. The clear upper layer solution was analyzed by a Milton Roy Spectronic 3000 Array spectrophotometer (New York, USA).The photocatalytic degradation rate of the samples were calculated according to the lambert beer''s law. The degradation rate of WO3/DWCNTs and pure WO3 is 87.50% and 25.39% respectively under photocatalytic degradation for 30 min. Results show that as the size of particles decreases, the specific surface area increases, and the adsorption capability of WO3/DWCNTs is improved; all these effects are ascribed to the addition of DWCNTs.Therefore, the WO3/DWCNTs composite photocatalyst exhibits much higher photocatalytic activity than that of pure WO3.