Abstract In this study, carbon-encapsulated hematite nanocubes with an edge length of ~20 nm (α-Fe2O3@C) were prepared by a two-step hydrothermal method using glucose as a carbon source. The α-Fe2O3@C nanocomposite was found to exhibit enhanced adsorption efficiency for inorganic chromium (VI) ions as compared to bare α-Fe2O3 nanocubes. At optimized conditions, the maximum adsorption capacity and removal efficiency of Cr(VI) using α-Fe2O3@C nanocomposites were 76.92 mg g−1 and 97.6%. The influence of carbon content on the structural features, and on the mechanism of adsorption of the α-Fe2O3@C nanocomposites were investigated and discussed. Adsorption data revealed that the adsorption behavior of the α-Fe2O3@C nanocomposites for chromium (VI) showed good agreement with both Langmuir and pseudo-second-order kinetic models. Moreover, the α-Fe2O3@C nanocomposites still retain high chromium (VI) removal efficiency after three recycles. Carbon-encapsulated hematite nanocubes with high Cr(VI) removal efficiency and excellent regenerability will become a promising absorbent toward the treatment of heavy metals from water solution.

中文翻译：

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通过使用碳包封的赤铁矿纳米立方体提高无机铬 (VI) 离子的吸附效率

摘要 在本研究中，以葡萄糖为碳源，通过两步水热法制备了边长约 20 nm 的碳包覆赤铁矿纳米立方体（α-Fe2O3@C）。与裸露的 α-Fe2O3 纳米立方体相比，发现 α-Fe2O3@C 纳米复合材料对无机铬 (VI) 离子的吸附效率更高。在优化条件下，使用 α-Fe2O3@C 纳米复合材料对 Cr(VI) 的最大吸附容量和去除效率为 76.92 mg g-1 和 97.6%。研究和讨论了碳含量对α-Fe2O3@C纳米复合材料结构特征和吸附机理的影响。吸附数据表明，α-Fe2O3@C 纳米复合材料对铬（VI）的吸附行为与 Langmuir 和准二级动力学模型非常吻合。而且，α-Fe2O3@C 纳米复合材料在 3 次循环后仍保持较高的铬 (VI) 去除效率。碳包封的赤铁矿纳米立方体具有高 Cr(VI) 去除效率和优异的可再生性，将成为处理水溶液中重金属的有前途的吸收剂。