Flexible Z-scheme heterojunction membrane reactors for visible-light-driven antibiotic degradation and oil-water separation

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 471; p. 144447
• Main Authors: Feng, Xiaofang, Long, Runxuan, Liu, Chenchen, Lu, Ying, Liu, Xiaobo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2023
• Subjects: Nano-functionalized; Photocatalytic membrane reactor; Self-assembled; Solvent-nonsolvent induced phase separation; Z-scheme; Solvent-nonsolvent induced phase separation; Photocatalytic membrane reactor; Nano-functionalized; Z-scheme; Self-assembled
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2023.144447

In this study, to overcome the problems of photo corrosion and structural instability, an attempt was made to construct a semiconductor heterojunction with MOF that can resist photo corrosion and reduction to adjust the electron (e−) transport path. The crystal stability and photo corrosion resistance are improved by creating Z-type heterojunctions to change the electron transfer path of Ag photocatalysts. MOFs have unique optical, electrical, and catalytic properties and thus play a key role in optimizing electron transfer pathways. Even if a semiconductor-catalyst heterojunction is constructed, migration-matched catalysts induce a cascade of crystal reduction and photo corrosion in a built-in electric field. At this time, PENS provides an electron acceptor platform, which can temporarily store photoelectrons, prevent the decrease of photoelectrons to the crystal, and improve electron transfer efficiency. The degradation of antibiotics and dyes assessed the resulting impact on photocatalytic efficiency under simulated sunlight, and photocatalytic activity was measured with an eye toward real outdoor applications. Due to the synergistic effect of the double self-cleaning structure, the ultrafiltration membrane exhibits superhydrophilic/underwater superoleophobic properties. It shows excellent separation efficiency and recyclability in the separation of oil-in-water emulsion experiments. [Display omitted] •Z-scheme facilitates the separation and transfer of charge carriers.•Flexibility, temperature resistance and acid and alkali resistance were achieved.•Membrane reactor exhibits efficient photocatalytic mineralization of antibiotics.•Superhydrophilic/underwater superoleophobic to achieve efficient oil-water separation.•Very robust performance over re-use cycles (×8 times) was achieved. This study fabricated PENS/TA/ZIF-67@Ag2S (PZA), a double self-cleaning network antifouling polymer membrane reactor, by the non-solvent-induced phase separation (NIPS) method. Due to the synergistic effect of the double self-cleaning structure, it showed an excellent separation efficiency of 99.65% and a high flux of 1198.011 L·m−2·h−1 in the separation of oil-in-water emulsion experiments. After eight cycles, Oil-water separation efficiency remains >99% recyclable. The Z-type heterogeneous conjunctival reactor we constructed has a high-efficiency degradation rate of 99.94% and a mineralization rate of 80.315% for sulfamethoxazole (SMX) within 120 min. From the results of mechanical properties, TGA and DSC, it can be seen that PZA has good strength, toughness and high temperature resistance. According to the experimental analysis of active substances, the active ingredients produced by PZA are •OH., h+, •O2–. Based on Density functional theory (DFT) calculations and intermediate analysis, sulfamethoxazole's active sites and degradation pathways (SMX) were explored. According to the Quantitative Structure-Activity Relationship (QSAR) of the Toxicity Estimation Software Tool (TEST), the toxicity of the intermediates produced during the degradation of SMX was predicted. This study provides a feasible strategy for fabricating Z-scheme metal-organic framework (MOF)-based polymer membrane reactors for efficient green antibiotic wastewater treatment and oil-water self-cleaning.