Department of Chemistry, Shiraz Branch, Islamic Azad University, P.O. Box 71955-149, Shiraz, Fars, Iran.
Department of Chemistry, Faculty of Science, University of Zabol, Zabol, Iran.
J Colloid Interface Sci. 2015 Feb 15;440:189-97. doi: 10.1016/j.jcis.2014.10.053. Epub 2014 Nov 4.
Heterogeneous Mn nanoparticles (5-30 nm diameter) is found to be a nanomaterial for the rapid removal of large quantities of toxic dye (methyl orange) from aqueous solution, with wide ranging potential applications. The synthesized materials were characterized with different methods such as FT-IR spectroscopy, CHN elemental analysis, BET, SEM, TEM, ICP-OES and EPR. The contact time to obtain equilibrium for maximum adsorption of methyl orange was 20 min. EPR of Mn ions evidenced that most of the covalently bond active sites of the nano-adsorbent are in the form of Mn(III) ions at the surface. The heterogeneous Mn(III)-Cl ions were found to be effective adsorbent for the removal of methyl orange from solution. The adsorption of methyl orange ions has been studied in terms of pseudo-first-order and pseudo-second-order kinetics, and the Freundlich, Langmuir and Langmuir-Freundlich isotherm models have also been applied to the equilibrium adsorption data. The adsorption process was spontaneous and endothermic in nature and followed pseudo-second-order kinetic model.
发现不同尺寸的（5-30nm）的纳米 Mn 颗粒是一种纳米材料，可以快速去除大量有毒染料（甲基橙），具有广泛的潜在应用。合成材料采用不同的方法进行了表征，如 FT-IR 光谱、CHN 元素分析、BET、SEM、TEM、ICP-OES 和 EPR。获得最大甲基橙吸附平衡的接触时间为 20 分钟。EPR 结果表明，纳米吸附剂表面的共价键活性位主要以 Mn(III)离子的形式存在。发现异相 Mn(III)-Cl 离子是一种有效吸附剂，可从溶液中去除甲基橙。从准一级和准二级动力学角度研究了甲基橙离子的吸附，同时还应用了 Freundlich、Langmuir 和 Langmuir-Freundlich 等温吸附模型对平衡吸附数据进行了拟合。吸附过程本质上是自发和吸热的，符合准二级动力学模型。
