In this work, a MXene composited cysteine-grafted hydroxyethyl methacrylate hydrogel (PHGC/MXene) was successfully synthesized, exhibiting excellent cycle stability and high selectivity toward ionic dyes at different pH. In mixed dyes system, PHGC/MXene exhibited remarkable adsorption selectivity and excellent property of pH-responsivenes for methyl blue (AB93) at pH=2.0 and for methylene blue (MB) at pH=11.0, with maximum adsorption capacity of 207.47 mg/g and 555.56 mg/g, respectively. Even after 12 desorption-regeneration cycles, the removal rates for AB93 and MB remained above 90 %. The study further analyzed the dynamic fixed-bed adsorption behavior of PHGC/MXene for MB, revealing optimal conditions at an inlet concentration of 75 mg/L MB dye and a bed depth of 9 cm. The adsorption mechanism was proposed combined with molecular dynamics simulations. PHGC/MXene emerges as an easily synthesized, highly selective adsorbent with significant potential for the purification of dyes from wastewater in both strongly acidic and strongly alkaline environments.

中文翻译：

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使用 MXene 复合 L-半胱氨酸接枝 HEMA 水凝胶响应 pH 值去除废水中的染料：动力学、选择性、再生和机制


本工作成功合成了MXene复合半胱氨酸接枝甲基丙烯酸羟乙酯水凝胶（PHGC/MXene），在不同pH值下表现出优异的循环稳定性和对离子染料的高选择性。在混合染料体系中，PHGC/MXene对pH=2.0的甲基蓝（AB93）和pH=11.0的亚甲基蓝（MB）表现出显着的吸附选择性和优异的pH响应性，最大吸附容量为207.47 mg/g和 555.56 毫克/克，分别。即使经过12次解吸-再生循环后，AB93和MB的去除率仍保持在90%以上。该研究进一步分析了 PHGC/MXene 对 MB 的动态固定床吸附行为，揭示了 MB 染料入口浓度为 75 mg/L、床层深度为 9 cm 时的最佳条件。结合分子动力学模拟提出了吸附机理。 PHGC/MXene 是一种易于合成、高选择性的吸附剂，在强酸性和强碱性环境中具有从废水中纯化染料的巨大潜力。