作者：Ji Shu, Yichong Zhang, Kanming Wang, Jianli Wang, Jiaxuan Ying, Hongyu Wang
关键字：Membrane hybrid system，Self-cleaning，Catalytic membrane，Ohmic contact，Advanced wastewater treatment
论文来源：期刊
具体来源：Chemical Engineering Journal
发表时间：2024年

膜过滤技术被视为水处理领域极具前景的技术之一，但其对微污染物的去除效率不足及膜污染问题仍制约着进一步应用。为此，本研究通过组装层状MXene与六方氮化硼（h-BN），构建了一种兼具药物高效去除与膜自清洁功能的新型杂化膜系统。当MXene以1:10的质量比掺杂于h-BN时，系统实现了吸附与光催化降解的协同作用。基于实验与密度泛函理论（DFT）计算结果，MXene的终端基团与导电特性显著提升了1/10 MXene@h-BN杂化膜体系的化学吸附-光降解性能。此外，该膜对甲氧苄啶（TMP）的降解行为符合Langmuir-Hinshelwood动力学模型，表明在模拟太阳辐照下，污染物去除不仅发生在膜表面，也可通过体相溶液中的反应实现。此现象归因于MXene@h-BN异质结内部能带结构改变形成的欧姆接触，促进了·OH与¹O₂活性物种的生成。通过本地污水处理厂二级出水进行的耐久性与实际应用测试表明，1/10 MXene@h-BN杂化膜在五次循环后仍保持较低膜污染率与稳定性能，验证了其优异的自清洁能力。同时，改性膜对二级出水的污染物截留率与通量均表现突出，证实了实际应用的可行性。基于上述优势，MXene@h-BN杂化膜有望成为深度废水处理的理想候选材料。

Membrane filtration is regarded as one of the promising technologies for water treatment. However, insufficient micropollutants removal and membrane fouling still limited the further application. Herein, this study engineered a novel membrane hybrid system integrating typical pharmaceuticals removal and membrane self-cleaning by assembled layered MXene and hexagonal boron nitride (h-BN). By doping a small amount of MXene into h-BN (mass ratio of 1 to 10), the synergetic process of adsorption and photocatalytic degradation were achieved. Based on experimental and density functional theory (DFT) calculation results, the chemisorption-photodegradation performance of the membrane hybrid system assembled with 1/10 MXene@h-BN was significantly enhanced due to the termination group and conductive property of MXene. In addition, trimethoprim (TMP) degradation by the above membrane followed the Langmuir–Hinshelwood model, indicating pollutants removal initiated not only on the membrane surface but also in the bulk solution under simulated solar irradiation. This phenomenon was attributed to the generation of ·OH and ¹O₂ by forming Ohmic contact with altered internal band structure. The durability and practical experiments with secondary effluent from local wastewater treatment were also tested. The exceptional self-cleaning performance of the membrane hybrid system assembled with 1/10 MXene@h-BN was demonstrated by lower membrane fouling and maintaining durability even after five cycles. Furthermore, the performance (both pollutants removal and flux) of the modified membrane for secondary effluent treatment was also considerable, validating its potential for practical application. Owing to the excellent features, the membrane assembled with MXene@h-BN is anticipated to be an ideal candidate for advanced wastewater treatment.