School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, 411201, China.
Key Laboratory of Theoretical Organic Chemistry and Function Molecule, Ministry of Education, Xiangtan, 411201, China.
Environ Sci Pollut Res Int. 2019 Mar;26(9):8721-8736. doi: 10.1007/s11356-019-04352-6. Epub 2019 Feb 1.
A two-component material (FeO@CaSiO) with an FeO magnetite core and layered porous CaSiO shell from calcium nitrate and sodium silicate was synthesized by precipitation. The structure, morphology, magnetic properties, and composition of the FeO@CaSiO composite were characterized in detail, and its adsorption performance, adsorption kinetics, and recyclability for Cu, Ni, and Cr adsorption were studied. The FeO@CaSiO composite has a 2D core-layer architecture with a cotton-like morphology, specific surface area of 41.56 m/g, pore size of 16 nm, and pore volume of 0.25 cm/g. The measured magnetization saturation values of the magnetic composite were 57.1 emu/g. Data of the adsorption of Cu, Ni, and Cr by FeO@CaSiO fitted the Redlich-Peterson and pseudo-second-order models well, and all adsorption processes reached equilibrium within 150 min. The maximum adsorption capacities of FeO@CaSiO toward Cu, Ni, and Cr were 427.10, 391.59, and 371.39 mg/g at an initial concentration of 225 mg/L and a temperature of 293 K according to the fitted curve with the Redlich-Peterson model, respectively. All adsorption were spontaneous endothermic processes featuring an entropy increase, including physisorption, chemisorption, and ion exchange; among these process, chemisorption was the primary mechanism. FeO@CaSiO exhibited excellent adsorption, regeneration, and magnetic separation performance, thereby demonstrating its potential applicability to removing heavy metal ions.
一种由硝酸钙和硅酸钠沉淀合成的具有 FeO 磁铁矿核和层状多孔 CaSiO 壳的双组分材料（FeO@CaSiO）。详细表征了 FeO@CaSiO 复合材料的结构、形态、磁性能和组成，并研究了其对 Cu、Ni 和 Cr 吸附的吸附性能、吸附动力学和可回收性。FeO@CaSiO 复合材料具有 2D 核-层结构，形态为棉状，比表面积为 41.56 m/g，孔径为 16nm，孔体积为 0.25cm/g。磁性复合材料的磁化饱和值为 57.1 emu/g。FeO@CaSiO 对 Cu、Ni 和 Cr 的吸附数据均较好地符合 Redlich-Peterson 和准二级模型，所有吸附过程在 150min 内达到平衡。根据 Redlich-Peterson 模型拟合曲线，FeO@CaSiO 对 Cu、Ni 和 Cr 的最大吸附容量分别为 427.10、391.59 和 371.39mg/g，初始浓度为 225mg/L，温度为 293K。所有吸附均为自发吸热过程，熵增加，包括物理吸附、化学吸附和离子交换；其中化学吸附是主要机制。FeO@CaSiO 表现出优异的吸附、再生和磁分离性能，因此具有去除重金属离子的潜在适用性。
