Abstract In the current study, pure and manganese-doped superparamagnetic iron oxide nanoparticles (Mn-doped SPIONPs) were successfully prepared by a green approach using a fresh aqueous extract of Asparagus officinalis as a reducing and stabilizing agent. Magnetic behaviors of pure and Mn-doped SPIONPs were measured at room temperature against various field strengths by a vibrating sample magnetometer (VSM). The saturation magnetization was in the range of 5.39–2.07 emu. Absorption at 340 nm in the UV-visible spectrum confirmed the presence of iron oxide nanoparticles (IONPs). The presence of plant extract as a capping agent was confirmed by Fourier transform infrared (FTIR) spectroscopy. The crystalline nature of IONPs was confirmed by X-ray diffraction. A gradual increase in size was observed with increasing concentration of Mn. The synthesized materials were applied successfully as sorbent for the effective removal of lead ions (Pb(ii)). Experimental results of adsorption were also analyzed by Langmuir and Freundlich isotherm equations at different temperatures. The results suggested that sorption processes were spontaneous, and the synthesized SPIONPs displayed PbII removal capacity at higher loadings with q m of 21.3 and 29.56 mg·g−1 for undoped and 7% Mn-doped IOPNs, respectively, as compared to the commercial activated carbon.

中文翻译：

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绿色合成锰掺杂超顺磁性氧化铁纳米颗粒，有效去除水溶液中的 Pb(ii)

摘要 在目前的研究中，以芦笋的新鲜水提取物为还原剂和稳定剂，通过绿色方法成功制备了纯锰掺杂超顺磁性氧化铁纳米粒子（Mn掺杂SPIONPs）。通过振动样品磁力计 (VSM) 在室温下针对各种场强测量纯和 Mn 掺杂 SPIONP 的磁行为。饱和磁化强度在 5.39-2.07 emu 范围内。在紫外-可见光谱中在 340 nm 处的吸收证实了氧化铁纳米颗粒 (IONP) 的存在。傅里叶变换红外 (FTIR) 光谱证实了植物提取物作为封端剂的存在。X射线衍射证实了IONP的结晶性质。随着 Mn 浓度的增加，观察到尺寸逐渐增加。合成的材料成功地用作吸附剂以有效去除铅离子 (Pb(ii))。吸附实验结果也通过Langmuir和Freundlich等温方程在不同温度下进行了分析。结果表明吸附过程是自发的，与商业活性炭相比，合成的 SPIONPs 在较高负载下显示出 PbII 去除能力，未掺杂和 7% Mn 掺杂的 IOPNs 的 qm 分别为 21.3 和 29.56 mg·g-1 .