In this study, a green synthesis method for synthesizing a novel nanocomposite (CuO/g-C₃N₄/Fe₃O₄) utilizing renewable dragon fruit peels as the primary raw material was developed. Hydrothermal and thermal decomposition techniques were used for nanocomposite synthesis. This nanocomposite was subsequently employed for the adsorption and preconcentration of Cd(II) from various environments, including food and water samples. Characterization of the nanocomposite was conducted utilizing FTIR, XRD, and SEM, which confirmed the successful combination of both metal oxides with g-C₃N₄ within the composite structure. The method exhibited efficient extraction of Cd (II) with a limit of detection (LOD) of 0.65 μg L⁻¹ and high recovery values (84–108 %) in real sample analyses. Optimization of parameters, including pH (8.0), adsorbent quantity (10 mg), and vortex mixing times (1 min for both), were studied to enhance extraction efficiency. This method demonstrates significant potential for environmental applications and provides a low-cost and sustainable approach for separating/enriching trace heavy metals, like Cd (II), with minimal environmental impact.

中文翻译：

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环保合成 CuO/g-C₃N₄/Fe₃O₄ 纳米复合材料，用于食品和水样品中痕量镉的高效磁性微固相萃取 （M-μ-SPE）


本研究开发了一种以可再生火龙果皮为主要原料合成新型纳米复合材料 （CuO/g-C₃N₄/Fe₃O₄） 的绿色合成方法。水热和热分解技术用于纳米复合材料合成。这种纳米复合材料随后用于吸附和预浓缩各种环境（包括食品和水样品）中的 Cd（II）。利用 FTIR、XRD 和 SEM 对纳米复合材料进行了表征，证实了两种金属氧化物在复合材料结构中与 g-C₃N₄ 的成功结合。该方法可高效提取 Cd （II），检测限 （LOD） 为 0.65 μg ^L-1，在实际样品分析中回收率高 （84-108%）。研究了包括 pH 值 （8.0）、吸附剂数量 （10 mg） 和涡旋混合时间（两者均为 1 min）在内的参数的优化，以提高提取效率。该方法在环境应用方面具有巨大的潜力，并为分离/富集痕量重金属（如 Cd （II））提供了一种低成本和可持续的方法，对环境的影响最小。