ABSTRACT Fe3O4 nanoparticles were prepared by co-precipitation of Fe2+ and Fe3+ and then modified with Au to produce an effective adsorbent (Fe3O4/Au) for aqueous Hg(II) in contaminated water. Rietveld refinement on the XRD pattern confirmed that the Fe3O4/Au was synthesised. Mössbauer spectra exhibited broad and asymmetric resonance lines with two sextets which can be assigned to tetrahedral Fe3+; and octahedral Fe3+/Fe2+. The quantitative analysis of magnetite confirms that the sample shows around 3 wt.% Au and 97 wt.% partially oxidised Fe3O4. High surface area: 121 m2 g−1, average pore sizes: 6.3 nm and pore volume: 1.64 cm3 g−1. The kinetics data were better fitted with a pseudo-second-order and Dubinin–Radushkevich isotherm suggests the Hg(II) adsorption onto Fe3O4/Au nanoparticles was mainly by chemical adsorption forming complex with the Au metal immobilised on Fe3O4 surfaces. Adsorption capacity of 79.59 mg g−1. Ionic strength and co-existing ions had a slight influence on the adsorption capacity. GRAPHICAL ABSTRACT

中文翻译：

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金功能化的 Fe3O4 磁性纳米颗粒从污染水中去除汞 (II)

摘要 Fe3O4 纳米粒子是通过 Fe2+ 和 Fe3+ 的共沉淀制备的，然后用 Au 改性，以产生一种有效的吸附剂（Fe3O4/Au），用于污染水中的 Hg(II) 水溶液。XRD 图上的 Rietveld 精修证实合成了 Fe3O4/Au。Mössbauer 光谱表现出宽且不对称的共振线，具有两个六重奏，可以分配给四面体 Fe3+；和八面体 Fe3+/Fe2+。磁铁矿的定量分析证实，样品显示大约 3 wt.% 的 Au 和 97 wt.% 部分氧化的 Fe3O4。高表面积：121 m2 g-1，平均孔径：6.3 nm，孔体积：1.64 cm3 g-1。动力学数据更符合伪二阶和 Dubinin-Radushkevich 等温线表明 Hg(II) 吸附到 Fe3O4/Au 纳米颗粒上主要是通过化学吸附与固定在 Fe3O4 表面上的 Au 金属形成络合物。79.59 mg g-1 的吸附容量。离子强度和共存离子对吸附容量有轻微影响。图形概要