多孔磁性氧化物纳米颗粒的合成、表面调控及其表面吸附性质研究
发布时间：2018-12-27 06:31
【摘要】：磁性纳米颗粒因其具有良好的吸附性能以及磁分离、磁场中定向移动等特性,在环境污染治理和纳米药物载体等领域展现出良好的潜在应用前景。从磁性纳米颗粒在水污染处理领域的应用出发,设计合成了一系列具有良好吸附性能的多孔磁性氧化物。以所合成的多孔磁性氧化物为吸附剂,研究了其对偶氮染料及重金属离子等一系列污染物的吸附性能。探讨了影响吸附量的若干重要因素,如吸附时间、p H、离子强度、温度等。并根据吸附过程中的热、动力学数据,提出了相应的吸附机理。论文的主要内容包括:(1)通过简单的两步反应合成了磁分离型铁氧体Ni0.6Fe2.4O4以及Co0.6Fe2.4O4纳米颗粒。研究了Ni0.6Fe2.4O4对刚果红,Co0.6Fe2.4O4对Pb2+的吸附性能,结果显示所得材料对水体污染物具有良好的移除能力。研究了p H值、离子强度、温度和吸附时间等因素对吸附性能的影响。结果表明,刚果红在Ni0.6Fe2.4O4以及Pb2+在Co0.6Fe2.4O4上的动力学过程,符合准二级吸附动力学过程。刚果红在Ni0.6Fe2.4O4上的吸附随着温度的增加而降低,而Pb2+在Co0.6Fe2.4O4上的吸附随着温度的升高而增大。通过对热力学参数(ΔH°,ΔS°,ΔG°)进行计算可知刚果红在Ni0.6Fe2.4O4上的吸附以及Pb2+在Co0.6Fe2.4O4上的吸附都是热力学自发过程。刚果红在Ni0.6Fe2.4O4吸附作用机制为静电引力,而Pb2+在Co0.6Fe2.4O4上的吸附作用机制属于离子交换。(2)以α-Fe2O3为起始原料,通过简单的碳热反应,制备了C/Fe3O4复合材料。与磁性氧化铁相比,α-Fe2O3是一种更加容易得到的原料。我们利用海藻酸钠辅助法,以具有不同形貌的α-Fe2O3为原料,合成了两种具有不同形貌的C/Fe3O4复合吸附剂。该方法具有普适性,利用市售的α-Fe2O3作为原料,通过该方法同样可以得到C/Fe3O4复合吸附剂。对该系列吸附剂的形貌、尺寸以及比表面积等微观结构进行了表征。研究了温度和吸附时间等因素对几种磁分离型吸附剂移除亚甲基蓝性能的影响。结果表明,亚甲基蓝在这三种不同形貌的复合吸附剂上吸附的动力学过程,均符合准二级吸附动力学过程。此外,该吸附过程的速率控制步骤(RDS)为表面扩散过程。
[Abstract]:Due to their good adsorption properties, magnetic separation and directional movement in magnetic field, magnetic nanoparticles have shown good potential applications in the field of environmental pollution control and nano-drug carriers. Based on the application of magnetic nanoparticles in water pollution treatment, a series of porous magnetic oxides with good adsorption properties were designed and synthesized. The adsorption properties of porous magnetic oxides for a series of pollutants such as azo dyes and heavy metal ions were studied. Some important factors affecting adsorption amount, such as adsorption time, p H, ion strength and temperature, were discussed. According to the data of heat and kinetics in the adsorption process, the adsorption mechanism was put forward. The main contents of this paper are as follows: (1) Ni0.6Fe2.4O4 and Co0.6Fe2.4O4 nanoparticles were synthesized by simple two-step reaction. The adsorption properties of Ni0.6Fe2.4O4 to Congo red and Co0.6Fe2.4O4 to Pb2 were studied. The results show that the obtained materials have good removal ability to water pollutants. The effects of pH, ionic strength, temperature and adsorption time on the adsorption properties were studied. The results show that the kinetic processes of Congo red on Ni0.6Fe2.4O4 and Pb2 on Co0.6Fe2.4O4 are in accordance with the quasi-second-order adsorption kinetic process. The adsorption of Congo red on Ni0.6Fe2.4O4 decreases with the increase of temperature, while the adsorption of Pb2 on Co0.6Fe2.4O4 increases with the increase of temperature. The calculation of thermodynamic parameters (螖 H 掳, 螖 S 掳, 螖 G 掳) shows that the adsorption of Congo red on Ni0.6Fe2.4O4 and the adsorption of Pb2 on Co0.6Fe2.4O4 are thermodynamic spontaneous processes. The adsorption mechanism of Congo red on Ni0.6Fe2.4O4 is electrostatic force, while the adsorption mechanism of Pb2 on Co0.6Fe2.4O4 belongs to ion exchange. (2) 伪-Fe2O3 is used as the starting material through a simple carbothermal reaction. C/Fe3O4 composites were prepared. 伪-Fe2O3 is a more readily available raw material than magnetic ferric oxide. Two kinds of C/Fe3O4 composite adsorbents with different morphologies were synthesized from 伪-Fe2O3 with different morphologies by sodium alginate assisted method. The method is universal. Using 伪-Fe2O3 as raw material, the C/Fe3O4 composite adsorbent can also be obtained by this method. The morphology, size and specific surface area of the adsorbent were characterized. The effects of temperature and adsorption time on the removal of methylene blue by magnetic separation adsorbents were studied. The results show that the kinetic process of methylene blue adsorption on the three kinds of composite adsorbents with different morphology is in accordance with the quasi-second-order adsorption kinetic process. In addition, the rate control step of the adsorption process, (RDS), is a surface diffusion process.
【学位授予单位】：聊城大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ424;TB383.1
本文编号：2392626
[Abstract]:Due to their good adsorption properties, magnetic separation and directional movement in magnetic field, magnetic nanoparticles have shown good potential applications in the field of environmental pollution control and nano-drug carriers. Based on the application of magnetic nanoparticles in water pollution treatment, a series of porous magnetic oxides with good adsorption properties were designed and synthesized. The adsorption properties of porous magnetic oxides for a series of pollutants such as azo dyes and heavy metal ions were studied. Some important factors affecting adsorption amount, such as adsorption time, p H, ion strength and temperature, were discussed. According to the data of heat and kinetics in the adsorption process, the adsorption mechanism was put forward. The main contents of this paper are as follows: (1) Ni0.6Fe2.4O4 and Co0.6Fe2.4O4 nanoparticles were synthesized by simple two-step reaction. The adsorption properties of Ni0.6Fe2.4O4 to Congo red and Co0.6Fe2.4O4 to Pb2 were studied. The results show that the obtained materials have good removal ability to water pollutants. The effects of pH, ionic strength, temperature and adsorption time on the adsorption properties were studied. The results show that the kinetic processes of Congo red on Ni0.6Fe2.4O4 and Pb2 on Co0.6Fe2.4O4 are in accordance with the quasi-second-order adsorption kinetic process. The adsorption of Congo red on Ni0.6Fe2.4O4 decreases with the increase of temperature, while the adsorption of Pb2 on Co0.6Fe2.4O4 increases with the increase of temperature. The calculation of thermodynamic parameters (螖 H 掳, 螖 S 掳, 螖 G 掳) shows that the adsorption of Congo red on Ni0.6Fe2.4O4 and the adsorption of Pb2 on Co0.6Fe2.4O4 are thermodynamic spontaneous processes. The adsorption mechanism of Congo red on Ni0.6Fe2.4O4 is electrostatic force, while the adsorption mechanism of Pb2 on Co0.6Fe2.4O4 belongs to ion exchange. (2) 伪-Fe2O3 is used as the starting material through a simple carbothermal reaction. C/Fe3O4 composites were prepared. 伪-Fe2O3 is a more readily available raw material than magnetic ferric oxide. Two kinds of C/Fe3O4 composite adsorbents with different morphologies were synthesized from 伪-Fe2O3 with different morphologies by sodium alginate assisted method. The method is universal. Using 伪-Fe2O3 as raw material, the C/Fe3O4 composite adsorbent can also be obtained by this method. The morphology, size and specific surface area of the adsorbent were characterized. The effects of temperature and adsorption time on the removal of methylene blue by magnetic separation adsorbents were studied. The results show that the kinetic process of methylene blue adsorption on the three kinds of composite adsorbents with different morphology is in accordance with the quasi-second-order adsorption kinetic process. In addition, the rate control step of the adsorption process, (RDS), is a surface diffusion process.
【学位授予单位】：聊城大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ424;TB383.1
【参考文献】
相关期刊论文 前1条
1 吴德礼,朱申红;新型吸附剂的发展与应用[J];矿产综合利用;2002年01期
，本文编号：2392626
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