新型Mo基催化剂的制备及其对环境污染物的降解性能研究

发布时间：2019-07-05 06:42

【摘要】：三氧化钼有多种晶相,在合成过程中,不同合成方法,或者是同一合成方法不同合成条件都会影响其结构、形貌、性能。本研究以水热法为例,探讨了不同合成条件对MoO3的影响,并筛选出形貌均匀的MoO3作为主催化剂。鉴于纯相MoO3的催化氧化能力有限,因此本文重点研究了改性的Ce掺杂材料,比较不同降解条件、降解环境对材料降解性能的影响,提出节能环保、净化污染物的最优方案。本文主要研究内容和研究成果如下：(1)以四水合钼酸铵((NH4)6Mo7O24·4H2O)为钼源,与稀硝酸水热反应合成六方相三氧化钼(h-MoO3),同时考察了反应温度、反应时间、硝酸含量对产物结构的影响。(2)以MoO3为主催化剂,以不同含量的Ce(NO3)3·6H2O溶液为Ce源,采用浸渍煅烧法制备一系列CeO2掺杂的MoO3 (Ce(x)/MoO3,x代表CeO2在MoO3中的质量百分数)。同时运用SEM、XRD、HRTEM、SAED、FT-IR等分析手段对催化材料进行一系列表征。(3)考察催化剂的催化性能,分别在无光照/有光照(可见光)条件下降解有机污染物亚甲基蓝(MB)、甲基橙(MO)。研究表明Ce(5)/MoO3催化氧化性能优良,与纯相MoO3催化活性相比,无光、有光条件下催化剂性能均提高了百倍以上。其中在可见光条件下,掺杂材料的带隙显著减小,因此光吸收能力也将明显增强,光催化性能随之提高。在本论文中,首先探究了催化材料的在无光条件下的催化性能,从节能环保角度,为环境污染物的降解提供了新思路。同时本文也首次将Ce掺杂的MoO3材料运用于光催化领域,其展现出的良好降解性能为扩展Mo基掺杂材料指明了新的应用及发展方向。
文内图片：图４－９邋Ｃｅ（ｘ）／邋Ｍ０Ｏ３和Ｃｅ0２的紫外漫反射光谱图逡逑Ｆｉｇ．４－９邋ｐｉｃａ］邋ＵＶ－ｖｉｓ邋ｄｉｆｆｕ化邋ｒｅｆｌｅｃ巧ｎｅｅ邋ｓｅｃｔｒａ邋ｏｆ邋Ｃｅｘ／邋Ｍｏ0邋ａｎｄｕｒｅ邋Ｃｅ0逡逑

图片说明：图４－９邋Ｃｅ（ｘ）／邋Ｍ０Ｏ３和Ｃｅ0２的紫外漫反射光谱图逡逑Ｆｉｇ．４－９邋ｐｉｃａ］邋ＵＶ－ｖｉｓ邋ｄｉｆｆｕ化邋ｒｅｆｌｅｃ巧ｎｅｅ邋ｓｅｃｔｒａ邋ｏｆ邋Ｃｅｘ／邋Ｍｏ0邋ａｎｄｕｒｅ邋Ｃｅ0逡逑
[Abstract]:There are many crystal phases of Mo _ 2O _ 3. In the process of synthesis, different synthesis methods, or different synthesis conditions, will affect the structure, morphology and properties of Mo _ 2O _ 3. In this study, taking hydrothermal method as an example, the effects of different synthesis conditions on MoO3 were discussed, and MoO3 with uniform morphology was selected as the main catalyst. In view of the limited catalytic oxidation ability of pure phase MoO3, the modified Ce doping materials were studied in this paper. the effects of different degradation conditions and degradation environment on the degradation properties of the materials were compared, and the optimal scheme of energy saving and environmental protection and purification of pollutants was put forward. The main contents and research results of this paper are as follows: (1) hexagonal molybdate trioxide (h-MoO3) was synthesized by hydrothermal reaction of ammonium molybdate tetrahydrate (NH4) 6Mo7O24 路4H2O) with dilute nitric acid. The effects of reaction temperature, reaction time and nitric acid content on the structure of the product were investigated. (2) MoO3 was used as catalyst and Ce (NO3) 3 路6H2O solution with different content was used as Ce source. A series of CeO2-doped MoO3 (Ce (x) / MoO3,x were prepared by impregnation and calcination method, which represented the mass percentage of CeO2 in MoO3. At the same time, a series of characterization of catalytic materials were carried out by SEM,XRD,HRTEM,SAED,FT-IR and other analytical methods. (3) the catalytic performance of the catalyst was investigated, and the degradation of methylene blue (MB), methyl orange (MO). Without light / light (visible light) was investigated. The results show that the catalytic oxidation performance of Ce (5) / MoO3 is better than that of pure phase MoO3. Compared with pure phase MoO3, the catalyst performance is more than 100 times higher than that of pure phase MoO3. Under the condition of visible light, the band gap of the doped materials is significantly reduced, so the optical absorption capacity will also be significantly enhanced, and the photocatalytic performance will be improved. In this paper, the catalytic performance of catalytic materials under the condition of no light is investigated, which provides a new idea for the degradation of environmental pollutants from the point of view of energy saving and environmental protection. At the same time, Ce-doped MoO3 materials are also applied to the field of photocatalysis for the first time, and their good degradation performance indicates a new application and development direction for the expansion of Mo-based doping materials.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O643.36;X703

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