Magnetically recoverable Fe3O4/MoS2/BiOI microspheres for visible light water disinfection: molecular mechanism and transcriptomic insights
Magnetically recoverable Fe3O4/MoS2/BiOI microspheres for visible light water disinfection: molecular mechanism and transcriptomic insights
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DOI：
10.1016/j.seppur.2023.124140
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发表时间：
2023-05
影响因子：
8.6
通讯作者：
Yijun Shi;Jiaxin Ma;D. Hanigan;Yanan Chen;Yunkun Qian;Junhai Guo;D. An
中科院分区：
文献类型：
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作者：
Yijun Shi;Jiaxin Ma;D. Hanigan;Yanan Chen;Yunkun Qian;Junhai Guo;D. An
绿色能源驱动的光催化是理想的水净化技术。为了深入了解光催化灭活细菌的机理，合成了一种新型可见光驱动的Fe 3 O 4/MoS 2/BiOI（FMB）光催化剂，并以E.证实了大肠杆菌消毒。完全灭活E. FMB在30 mW/cm ~ 2的> 400 nm的光照射下100 min即可达到产率。FMB还能有效降低实际水源水中的细菌总数和异养菌数。光化学实验表明，H+、e-、H2 O2、1 O2和·O2-是导致失活的主要因素。半透膜实验提供了进一步的证据，即光催化剂和细菌之间的接触是实现灭活所必需的。在消毒过程中，细胞的zeta电位先降低后升高，而颗粒大小先增大后减小，表明细胞破裂。扫描电子显微镜、钾离子渗漏以及细胞表面疏水性和亲水性的变化都证实了E.大肠杆菌细胞膜在分子水平上。E.超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性先升高后降低，进一步表明细胞膜被破坏，细胞内容物渗漏。转录组学被用来了解基因表达，并确认细菌膜损伤后的氧化应激反应。这项工作提供了一个示范的FMB灭活可见光和机械的理解灭活ofE。杆菌
Photocatalysis driven by green energy is ideal for water purification. To gain a deeper understanding of the underlying mechanism behind the photocatalytic inactivation of bacteria, a novel visible-light-driven Fe3O4/MoS2/BiOI (FMB) photocatalyst was synthesized, andE. colidisinfection was demonstrated. Complete inactivation ofE. coliwas achieved in 100 min by FMB exposed to 30 mW/cm2of > 400 nm light. FMB can also effectively reduce the total number of bacteria and heterotrophic bacteria in actual source water. The photochemical experiments revealed that h+, e-, H2O2,1O2and •O2–were responsible for inactivation reactions. The semipermeable membrane experiments provided further evidence that contact between the photocatalyst and the bacteria was necessary to achieve inactivation. During the disinfection process, the zeta potential of the cells first decreased and then increased, while the particle size first increased and then decreased, indicating the rupture of the cells. Scanning electron microscopy, potassium ion leakage, and changes in cell surface hydrophobicity and hydrophilicity all confirmed the destruction of theE. colicell membrane at the molecular level. The β-GAL activity ofE. colidecreased, and the activities of superoxide dismutase (SOD) and catalase (CAT) increased initially, but subsequently decreased, further demonstrating disruption of the cell membrane and the leakage of cell contents. Transcriptomics was employed to understand gene expression and confirm bacterial membrane damage followed by oxidative stress response. This work provides a demonstration of the FMB inactivation by visible light and a mechanistic understanding of inactivation ofE. coli.