多孔分级结构AlOOH的无模板水热制备及吸附性能研究

发布时间：2017-12-27 00:08

本文关键词：多孔分级结构AlOOH的无模板水热制备及吸附性能研究　出处：《重庆理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文以无机盐作为沉淀剂、硝酸铝作为铝源,采用无模板水热法制备得到不同形貌的多孔分级结构勃姆石材料。研究了制备得到的勃姆石对有机染料的吸附性能。主要研究内容和结果如下:以碳酸氢钠和硝酸铝为原料进行水热反应,研究了碳酸氢钠浓度、硝酸铝浓度对产物形貌的影响。当硝酸铝浓度为10mmol,碳酸氢钠添加量为10mmol,在190℃下反应24h制备得到整体尺寸长约1.4μm,宽约0.7μm的形貌均一、分散性较好的椭圆状分级结构AlOOH材料。以草酸钠和硝酸铝为原料进行水热反应,研究了草酸钠添加量对产物形貌的影响。草酸钠为2mmol时,制备得到了由纳米窄片组装成的长度为1.7-2.2μm,宽度为0.8-1μm空心椭圆状分级结构。以磷酸氢二钠和硝酸铝为原料进行水热反应,研究了磷酸氢二钠添加量对产物形貌的影响。磷酸氢二钠为1mmol时,制备了结构形貌趋于单一、分散性良好,长度为3.3-4.0μm,两端宽度约为2.0μm,中间宽度约为1.1μm的连体捆束状分级结构勃姆石。以磷酸钠和硝酸铝为原料进行水热反应,研究了磷酸钠添加量对产物形貌的影响。磷酸钠为1mmol时,产物结构呈连体捆束形状,其结构形貌趋于单一、分散性良好,长度约为2.5-3.3μm,宽度约0.9-1.6μm。分级结构勃姆石的形成机理为,水热过程中,无机盐水解为游离态的铝离子提供出氢氧根离子生成氢氧化铝胶体,氢氧化铝胶体经溶解再结晶后形成勃姆石形态。勃姆石表面因吸附无机盐阴离子,改变了其表面的能量,生长方向发生改变。同时无机盐阴离子降低勃姆石粒子间的斥力,勃姆石在范德华力的作用下组装在一起,形成分级结构。利用制备的勃姆石对有机染料进行吸附实验,研究其吸附性能。结果表明勃姆石对刚果红表现出良好的吸附性能。对于碳酸氢体系,椭圆状分级结构产物表现出对刚果红的最大吸附量为97.9mg/g;对于草酸钠体系,添加量为2mmol得到的中空椭圆状分级结构对刚果红的最大吸附量为99mg/g;对于磷酸氢二钠体系,磷酸氢二钠添加量为0.5mmol得到的捆束状分级结构产物对刚果红的最大吸附量为98.6mg/g;对于磷酸钠体系,磷酸钠添加量为0.1mmol得到的捆束状分级结构产物对刚果红的最大吸附量为99.4mg/g。对于其它染料,制备的勃姆石对酸性铬兰K具有一定的吸附能力,对于亚甲基蓝则不具有吸附能力。
[Abstract]:In this paper, inorganic salts as agents, aluminum nitrate precipitation as aluminum source, using the template free hydrothermal preparation of different morphology porous hierarchical structure of boehmite materials. Study on the adsorption properties of the prepared boehmite for organic dyes. The main research contents and results are as follows: hydrothermal reaction is carried out with sodium bicarbonate and aluminum nitrate as raw materials, and the effects of sodium bicarbonate concentration and aluminum nitrate concentration on the morphology of products are studied. When the concentration of aluminum nitrate is 10mmol, the amount of sodium bicarbonate is 10mmol, and the reaction is 24h at 190 24h, the elliptical graded AlOOH material with uniform size and good dispersion is obtained, which has a size of about 1.4 m and a width of 0.7 m. The effects of sodium oxalate and aluminum nitrate on the morphology of the products were studied with sodium oxalate and aluminum nitrate as raw materials. When sodium oxalate is 2mmol, the structure of a hollow elliptical structure with a length of 1.7-2.2 mu m and a width of 0.8-1 mu m is obtained. The hydrothermal reaction was carried out with sodium hydrogen phosphate two and aluminum nitrate as raw materials. The effect of the addition of two sodium phosphate on the morphology of the products was studied. Two sodium hydrogen phosphate 1mmol, preparation of the structure tends to be single, good dispersion, length 3.3-4.0 m, width of both ends is about 2 m, the middle width is about 1.1 m conjoined bundle hierarchical structure of boehmite. The effects of sodium phosphate and sodium nitrate on the morphology of the products were studied with sodium phosphate and aluminum nitrate as raw materials. When sodium phosphate is 1mmol, the structure of the product is conjoined bundles. Its structure tends to be single, and its dispersion is good, the length is about 2.5-3.3 mu m, and the width is about 0.9-1.6 mu m. The formation mechanism of the hierarchical structure of boehmite, hydrothermal process, provide a hydroxyl ion generating inorganic salt solution for aluminum aluminum hydroxide colloid free metal ion, aluminum hydroxide colloid was dissolved after recrystallization formed boehmite morphology. Boehmite surface due to adsorption of anions, change the surface energy, the growth direction of change. At the same time reduce the boehmite particles of inorganic salt anion repulsion effect, boehmite in the van Edward assembled together to form a hierarchical structure. The organic dye adsorption experiments were carried out using the preparation of boehmite on its adsorption properties. The results show that boehmite on Congo red showed good adsorption properties. For the system of hydrogen carbonate, elliptical hierarchical structure product showed the maximum adsorption of Congo red was 97.9mg/g; the sodium oxalate system, the maximum adsorption capacity of hollow oval shaped hierarchical structure was added into 2mmol to the Congo red 99mg/g; for two sodium hydrogen phosphate system, the maximum adsorption capacity of two hierarchical structure product bundle sodium hydrogen phosphate was added to 0.5mmol to get to Congo red 98.6mg/g; for sodium phosphate system, the maximum adsorption capacity of hierarchical structure of product bundle sodium additives for 0.1mmol to get to Congo red 99.4mg/g. For other dyes, preparation of boehmite has certain adsorption ability of acid chrome blue K, for there is no adsorption capacity of methylene blue.
【学位授予单位】：重庆理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X703;TB383.4

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