【摘要】 石墨具有通过草酸介导Cr（Ⅵ）还原反应的潜力，但需通过合理改性以增强其电子传递能力。本研究将生物合成的施氏矿物（Sch）改性石墨（Sch@G）在700℃热解，用于Cr（Ⅵ）污染修复。结果表明，生物合成施氏矿物颗粒成功负载于石墨表面，提供了高比表面积和丰富的含氧官能团。在1 g/L Sch@G与1 mmol/L草酸的协同作用下，60 min内Cr（Ⅵ）去除率达90.42%。对比实验显示，改性材料（Sch@G）在宽pH范围（pH 2～10）内均表现优异，即使在pH=10时60 min去除率仍达97.9%。此外，该催化剂在含多种阴离子(Cl^-、SO₄^2-、NO₃^-、H₂PO₄^-)的溶液中均展现出卓越的环境适应性。机理分析表明，该催化剂显著促进了电子从草酸向Cr污染物的转移，同时施氏矿物中释放的低价铁离子进一步加速了电子传递至Cr污染物。此外，草酸可通过形成草酸-Cr（Ⅵ）络合物降低Cr（VI）活性，从而促进其后续去除。综上，催化剂与草酸的协同效应构建了一个高效体系，能在酸性至碱性条件下（pH 2～10）实现Cr（Ⅵ）污染物的快速高效修复。因此，该材料是一种极具应用前景的石墨基生物材料，可用于废水中Cr（Ⅵ）的快速高效治理。更多还原

【Abstract】 Graphite has the potential to mediate the reduction process of Cr（Ⅵ） by oxalic acid（OA）, but a reasonable modification is required to enhance the mediation of electron transfer. In this study, biosynthetic Schwertmannite（Sch）modified graphite（Sch@G） was pyrolyzed at 700℃ for Cr（Ⅵ） remediation. Biosynthetic Sch particles were successfully loaded on the graphite, providing high specific surface area and abundant O-containing functional groups. The removal efficiency of Cr（Ⅵ） reached 90.42% within 60 min, facilitated by the synergistic between 1 g/L Sch@G and 1 mmol/L OA. Additionally, the comparative experiments exhibited a significant capacity of Sch@G in a wide pH range（pH 2-10）,the removal efficiency was 97.9% within 60 min even at pH 10. Furthermore, the catalyst presented superior environmental adaptability in solutions containing various types of anions(Cl^-, SO₄^2-, NO₃^-, H₂PO₄^-). Mechanism analysis revealed that the catalyst greatly promotes the transfer of electrons from OA to Cr-contaminants, along with the release of low-valent Fe from Sch, enabling efficient electrons transfer to the Cr-contaminant. Meanwhile, the addition of OA could complex OA-Cr（Ⅵ） compound, lowering the activity of Cr（Ⅵ） and facilitating the subsequent Cr（Ⅵ）removal. Generally, the synergistic effect of the catalyst and OA can form an efficient system that enables rapid and effective remediation of Cr（Ⅵ） contamination across a wide pH range. Thus, the catalyst presents as a promising graphite-based biomaterial for the rapid and effective remediation of Cr（Ⅵ） contaminants from wastewater.更多还原