Abstract A novel nanocomposite, named as FCN, which was synthesized by loading FeS (Mackinawite) onto graphite phase carbon nitride (g-C3N4), was applied to remove Cr(VI) in aqueous solutions and characterized by SEM, BET, XRD, FTIR, Zeta and XPS. The effect of adsorption parameters including temperature, initial solution pH, FCN dosage, the initial concentration of Cr(VI), recycling performance of FCN and coexisting anions were investigated. Results revealed that the optimum adsorption capacity of the FCN for Cr(VI) was 61.8 mg/g at 298 K (pH = 3). Inorganic anions such as SO42−, NO3− and Cl− exhibited positive effect, while HCO3- inhibited the adsorption of Cr(VI). The adsorption kinetics of Cr(VI) followed the pseudo-second-order model and the adsorption process fitted the Langmuir model well. Thermodynamic results showed that the reaction process of FCN for Cr(VI) adsorption was an endothermic process with increasing entropy. The main mechanism of removing Cr(VI) by FCN were adsorption, chemical reduction and complexation. These results reveal that FCN will be a potential material for removing Cr(VI) from aqueous solutions.

中文翻译：

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FeS@石墨氮化碳纳米复合材料去除六价铬的性能和机理

摘要 在石墨相氮化碳 (g-C3N4) 上负载 FeS (Mackinawite) 合成了一种名为 FCN 的新型纳米复合材料，用于去除水溶液中的 Cr(VI)，并通过 SEM、BET、XRD、FTIR 进行表征。 、Zeta 和 XPS。研究了吸附参数的影响，包括温度、初始溶液 pH 值、FCN 用量、Cr(VI) 的初始浓度、FCN 的回收性能和共存阴离子。结果表明，FCN 对 Cr(VI) 的最佳吸附容量在 298 K（pH = 3）下为 61.8 mg/g。SO42-、NO3-和Cl-等无机阴离子表现出积极作用，而HCO3-则抑制了Cr(VI)的吸附。Cr(VI)的吸附动力学遵循准二级模型，吸附过程符合Langmuir模型。热力学结果表明，FCN吸附Cr(VI)的反应过程是一个熵增加的吸热过程。FCN去除Cr(VI)的主要机理是吸附、化学还原和络合。这些结果表明 FCN 将成为从水溶液中去除 Cr(VI) 的潜在材料。