Membrane hybrid system assembled with MXene@h-BN for efficient typical pharmaceuticals removal and self-cleaning: Synergetic effect on adsorption-photocatalytic process
作者：Ji Shu, Yichong Zhang, Kanming Wang, Jianli Wang, Jiaxuan Ying, Hongyu Wang
關鍵字：Membrane hybrid system，Self-cleaning，Catalytic membrane，Ohmic contact，Advanced wastewater treatment
論文來源：期刊
具體來源：Chemical Engineering Journal
發表時間：2024年
膜過濾技術被視為水處理領域極具前景的技術之一，但其對微污染物的去除效率不足及膜污染問題仍制約著進一步應用。為此，本研究通過組裝層狀MXene與六方氮化硼（h-BN），構建了一種兼具藥物高效去除與膜自清潔功能的新型雜化膜系統。當MXene以1:10的質量比摻雜于h-BN時，系統實現了吸附與光催化降解的協同作用。基于實驗與密度泛函理論（DFT）計算結果，MXene的終端基團與導電特性顯著提升了1/10 MXene@h-BN雜化膜體系的化學吸附-光降解性能。此外，該膜對甲氧芐啶（TMP）的降解行為符合Langmuir-Hinshelwood動力學模型，表明在模擬太陽輻照下，污染物去除不僅發生在膜表面，也可通過體相溶液中的反應實現。此現象歸因于MXene@h-BN異質結內部能帶結構改變形成的歐姆接觸，促進了·OH與1O2活性物種的生成。通過本地污水處理廠二級出水進行的耐久性與實際應用測試表明，1/10 MXene@h-BN雜化膜在五次循環后仍保持較低膜污染率與穩定性能，驗證了其優異的自清潔能力。同時，改性膜對二級出水的污染物截留率與通量均表現突出，證實了實際應用的可行性。基于上述優勢，MXene@h-BN雜化膜有望成為深度廢水處理的理想候選材料。
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.
