Abstract In the present study, iron oxide nanoparticles (FeONPs) were firstly synthesized using non-edible peel extracts of Citrus paradisi, which is abundantly available in the Andean Region, Latin America. Characterizations techniques like Visual, U.V.–Vis spectroscopy, Dynamic Light Scattering (DLS), Transmission electron microscopy (TEM) with Selected area electron diffraction (SAED), X- ray diffraction (XRD) and Thermogravimetric analysis (TGA) were performed for characterization of as-prepared material in terms of size, morphology, composition and structure. Furthermore, based on the Fourier-transform infrared spectroscopy (FTIR) analysis, a possible synthesis mechanism was proposed for the synthesis of FeONPs. The DLS shows that the FeONPs with average size of 27.1 ± 13.9 nm and TEM analysis confirms that the FeONPs are mostly spherical shape, aggregating in nature with an average size of 28–32 nm, respectively. XRD confirmed the existence of Fe3O4, α-Fe2O3 and γ-Fe2O3 nanoparticle mixture, whereas TG analysis indicated that the nanoparticles contain 76% metal,16% adsorbed moisture and 8% capping ligand. Finally, as prepared iron nanoparticles exhibited antioxidant activities against 1, 1-diphenyl-2-picrylhydrazyl (>15%, 100 µg) and also they were used for the treatment of different synthetic dyes (Methyl Rose, MR; Methylene Blue, MB and Methyl Orange, MO) to evaluate their adsorbity. The different decolourization percentages were obtained for the dyes MR (96.65%, 50 mg/L), MB (80.76%, 10 mg/L) and MO (89.64%,10 mg/L), respectively for 6 h at 25 °C. As a result, the use of agricultural waste as Citrus paradisi peel in nanoscience offers a sustainable, low cost, non toxic and friendly to the environment compared to other synthetic methods.

中文翻译：

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使用柑橘果皮生物合成氧化铁纳米颗粒的表征和应用：一种可持续的方法

摘要 在本研究中，氧化铁纳米颗粒 (FeONPs) 首先使用不可食用的柑橘果皮提取物合成，这种果皮提取物在拉丁美洲安第斯地区大量供应。表征技术如视觉、紫外-可见光谱、动态光散射 (DLS)、透射电子显微镜 (TEM) 与选区电子衍射 (SAED)、X 射线衍射 (XRD) 和热重分析 (TGA) 用于表征制备的材料在尺寸、形态、成分和结构方面。此外，基于傅里叶变换红外光谱（FTIR）分析，提出了合成 FeONPs 的可能合成机制。DLS 显示平均尺寸为 27.1 ± 13 的 FeONP。9 nm 和 TEM 分析证实 FeONPs 大多为球形，在自然界中聚集，平均尺寸分​​别为 28-32 nm。XRD 证实存在 Fe3O4、α-Fe2O3 和 γ-Fe2O3 纳米颗粒混合物，而 TG 分析表明纳米颗粒含有 76% 的金属、16% 的吸附水分和 8% 的封端配体。最后，制备的铁纳米颗粒对 1, 1-diphenyl-2-picrylhydrazyl (>15%, 100 µg) 表现出抗氧化活性，并且它们还用于处理不同的合成染料（甲基玫瑰，MR；亚甲蓝，MB 和甲基橙，MO）来评估它们的吸附性。染料 MR (96.65%, 50 mg/L), MB (80.76%, 10 mg/L) 和 MO (89.64%, 10 mg/L) 在 25 ℃ 6 h 得到不同的脱色率. 因此，