Lin Chun-Rong, Ivanova Oxana S, Petrov Dmitry A, Sokolov Alexey E, Chen Ying-Zhen, Gerasimova Marina A, Zharkov Sergey M, Tseng Yaw-Teng, Shestakov Nicolay P, Edelman Irina S
Department of Applied Physics, National Pingtung University, Pingtung City 90003, Taiwan.
Kirensky Institute of Physics, FRC KSC SB RAS, 660036 Krasnoyarsk, Russia.
Nanomaterials (Basel). 2021 Sep 12;11(9):2371. doi: 10.3390/nano11092371.
FeO@SiO core-shell nanoparticles (NPs) were synthesized with the co-precipitation method and functionalized with NH amino-groups. The nanoparticles were characterized by X-ray, FT-IR spectroscopy, transmission electron microscopy, selected area electron diffraction, and vibrating sample magnetometry. The magnetic core of all the nanoparticles was shown to be nanocrystalline with the crystal parameters corresponding only to the FeO phase covered with a homogeneous amorphous silica (SiO) shell of about 6 nm in thickness. The FT-IR spectra confirmed the appearance of chemical bonds at amino functionalization. The magnetic measurements revealed unusually high saturation magnetization of the initial FeO nanoparticles, which was presumably associated with the deviations in the Fe ion distribution between the tetrahedral and octahedral positions in the nanocrystals as compared to the bulk stoichiometric magnetite. The fluorescent spectrum of eosin Y-doped NPs dispersed in water solution was obtained and a red shift and line broadening (in comparison with the dye molecules being free in water) were revealed and explained. Most attention was paid to the adsorption properties of the nanoparticles with respect to three dyes: methylene blue, Congo red, and eosin Y. The kinetic data showed that the adsorption processes were associated with the pseudo-second order mechanism for all three dyes. The equilibrium data were more compatible with the Langmuir isotherm and the maximum adsorption capacity was reached for Congo red.
采用共沉淀法合成了FeO@SiO核壳纳米粒子（NPs），并用NH氨基进行功能化。通过X射线、傅里叶变换红外光谱、透射电子显微镜、选区电子衍射和振动样品磁强计对纳米粒子进行了表征。结果表明，所有纳米粒子的磁芯均为纳米晶体，其晶体参数仅对应于覆盖有厚度约为6nm的均匀非晶二氧化硅（SiO）壳的FeO相。傅里叶变换红外光谱证实了氨基功能化时化学键的出现。磁性测量显示初始FeO纳米粒子具有异常高的饱和磁化强度，这可能与纳米晶体中四面体和八面体位置的Fe离子分布与体相化学计量磁铁矿相比存在偏差有关。获得了分散在水溶液中的曙红Y掺杂纳米粒子的荧光光谱，并揭示和解释了红移和谱线展宽（与水中游离的染料分子相比）。重点研究了纳米粒子对三种染料：亚甲基蓝、刚果红和曙红Y的吸附性能。动力学数据表明，所有三种染料的吸附过程均符合准二级动力学机制。平衡数据与朗缪尔等温线更相符，刚果红达到了最大吸附容量。
