Synthesis of bimetallic Fe-Zn nanoparticles and its application towards adsorptive removal of carcinogenic dye malachite green and Congo red in water
Synthesis of bimetallic Fe-Zn nanoparticles and its application towards adsorptive removal of carcinogenic dye malachite green and Congo red in water
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DOI：
10.1016/j.molliq.2015.09.006
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发表时间：
2015-12-01
影响因子：
6
通讯作者：
Chattopadhyaya, Mahesh Chandra
中科院分区：
文献类型：
--
作者：
Gautam, Ravindra Kumar;Rawat, Vandani;Chattopadhyaya, Mahesh Chandra
采用共沉淀法合成了一种新型的纳米铁锌颗粒，并将其应用于对水中致癌染料孔雀石绿色（MG）和刚果红（CR）的吸附去除。采用TEM、XRD、FTIR、SEM、EDX、BET比表面积分析仪和pH（zpc）等手段对合成的Fe-Zn纳米粒子进行了表征。通过改变溶液pH值、吸附时间和染料初始浓度等优化参数，对吸附过程进行了评价。该过程最初非常迅速，在接触时间的60分钟内观察到最大吸附。去除动力学进行了测试与伪一阶，伪二阶，和颗粒内扩散模型，并显示出最好的协议与伪二阶模型。吸附数据与Langmuir，Freundlich，Temkin和Dubininin-Radushkevich等温线建模，并与Langmuir等温线模型有很好的拟合。结果表明，该树脂对MG和CR的最大吸附量分别为21.74和28.56 mg/g。吸附过程是吸热的，MG和CR的三角形H度分别为62.73和69.65 kJ/mol的正值，并且是自发的，因为三角形G度值对于所有样品均为负值。一个积极的AS值表示增加的障碍在固溶体界面的MG和CR染料的吸附过程中。尝试用合适的洗脱剂再生MG-和CR-负载的重氮化Fe-Zn纳米颗粒，并且再生的重氮化Fe-Zn纳米颗粒分别重复使用7次和6次，对于MG和CR的吸附去除水平高于70%。(C)2015 Elsevier B. V.版权所有。
In this study, a novel bimetallic Fe-Zn nanoparticle was synthesized via a coprecipitation method and applied for the adsorptive removal of carcinogenic dye malachite green (MG) and Congo red (CR) in water. The synthesized bimetallic Fe-Zn nanopartides were characterized by TEM, XRD, FTIR, and SEM with an attached EDX, a BET surface area analyzer, and by determining pH(zpc). Batch adsorption experiments were conducted to evaluate the adsorption process by varying the optimization parameters such as the solution pH, time, and initial dye concentration. The process was initially very rapid, and the maximum adsorption was observed within 60 min of contact time. The kinetics of removal were tested with a pseudo-first order, a pseudo-second order, and an intra-particle diffusion model and showed the best agreement with the pseudo-second order model. Adsorption data were modeled with Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms and had a good fit with the Langmuir isotherm model. The Langmuir maximum adsorption capacity for MG and CR was found to be 21.74 and 28.56 mg/g, respectively. The adsorption process was endothermic with positive values of triangle H degrees of 62.73 and 69.65 kJ/mol for MG and CR, respectively, and was spontaneous, as the triangle G degrees value was negative for all of the samples. A positive AS value indicates increased disorder at the solid-solution interface during the adsorption of the MG and CR dyes. An attempt was made to regenerate the MG-and CR-loaded bimetallic Fe-Zn nanoparticles with suitable eluents and the regenerated bimetallic Fe-Zn nanoparticles were reused seven and six times with removal levels higher than 70% for the adsorption of MG and CR, respectively. (C) 2015 Elsevier B.V. All rights reserved.