Ag NPs coated PVDF@TiO2 nanofiber membrane prepared by epitaxial growth on TiO2 inter-layer for 4-NP reduction application
Ag NPs coated PVDF@TiO2 nanofiber membrane prepared by epitaxial growth on TiO2 inter-layer for 4-NP reduction application
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DOI：
10.1016/j.seppur.2019.115700
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发表时间：
2019-11-15
影响因子：
8.6
通讯作者：
Xu, Zhi
中科院分区：
文献类型：
--
作者：
Wang, Yi-Xing;Ma, Shuai;Xu, Zhi
催化膜在环境治理中发挥着越来越重要的作用。本研究基于外延生长原理，在多孔PVDF@TiO2纳米纤维（NF）上生长Ag纳米颗粒，制备了一种新型催化膜。使用植入的TiO2 NPs作为中间层，Ag NPs可以紧密地涂覆在多孔PVDF@TiO2 NF的表面。所得NF膜可承受4小时的超声波清洗处理。然后，研究了通过使用 Ag 涂层 NF 膜过滤来还原 4-硝基苯酚 (4-NP)。 Ag涂层纳滤膜的通量达到580 Lm(-2) h(-1) bar(-1)，还原程度在96%以上。 Ag涂层PVDF纳滤膜的催化活性在7次重复操作循环中保持稳定，每次持续至少2小时。同时，计算出的表观反应速率常数远高于单一反应过程中报道的速率常数。为了探究其原因，提出了一种基于吸附反应路径的新机制来解释它们的协同效应。
The catalytic membrane plays an increasingly important role in the environmental remedy. In the present study, a novel catalytic membrane was prepared by growing Ag NPs on the porous PVDF@TiO2 nanofiber (NF) based on the epitaxial growth principle. Using the implanted TiO2 NPs as inter-layer, Ag NPs can be tightly coated to the surface of the porous PVDF@TiO2 NF. The obtained NF membrane can withstand the ultrasonic washing treatment of 4 hrs. Afterward, the reduction of 4-nitrophenol (4-NP) through the filtration using Ag coated NF membrane was investigated. The flux of Ag coated NF membrane reaches 580 Lm(-2) h(-1) bar(-1), and the reduction degree is above 96%. The catalytic activity of the Ag coated PVDF NF membrane remains stable during 7 repeated operation recycles, with each one lasting for at least 2 h. Meanwhile, the calculated apparent reaction rate constant is much higher than that reported in the single reaction process. To explore the reason, a new mechanism based on the adsorption-reaction path is proposed to explain their synergistic effect.