Photocatalytic inactivation of airborne bacteria in a polyurethane foam reactor loaded with a hybrid of MXene and anatase TiO2 exposing {001} facets
Photocatalytic inactivation of airborne bacteria in a polyurethane foam reactor loaded with a hybrid of MXene and anatase TiO2 exposing {001} facets
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在装有 MXene 和锐钛矿 TiO2 混合物的聚氨酯泡沫反应器中，暴露 {001} 面，光催化灭活空气中的细菌
DOI：
10.1016/j.cej.2020.126526
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发表时间：
2021-01-15
影响因子：
15.1
通讯作者：
Chen, Hong
中科院分区：
文献类型：
--
作者：
Lu, Siyi;Meng, Ge;Chen, Hong
本研究合成了一种TiO 2暴露{001}面和单层Ti（3）C（2）Tx纳米片（MXene）的混合物，表征并用作光催化剂。MXene（3.4wt%）的引入有助于减少光生电子和空穴的复合，从而使光催化活性提高30%。将制备的光催化剂涂敷在聚氨酯泡沫上，制成连续流动反应器，用于空气中细菌的降解。研究了光催化灭活空气中大肠杆菌（Escherichia coli，E. coli）在254（UV 254）紫外线照射下的菌体数量级达到3.4 lg，优于相同操作条件（相对湿度95%、停留时间4.27 s）下仅用UV 254处理的菌体数量级2.5 lg，为上级。研究了湿度和细菌种类对灭活效果的影响。较厚的细胞膜可以保护细菌免受光催化氧化，而高湿度通过产生更多的活性氧来提高光催化灭活效率。研究了气传大肠杆菌的光复活和暗修复现象。大肠杆菌使用UV 254单独处理观察。但紫外光催化失活后没有再活化，在可见光下甚至出现持续下降。这些结果表明，紫外线照射和紫外线照射灭活细菌的机制不同，前者通过破坏其DNA而灭活细菌，而后者则通过物理破坏其细胞结构。
A hybrid of TiO2 exposing {001} facets and monolayer Ti(3)C(2)Tx nanosheet (MXene) was synthesized, characterized and used as a photocatalyst in this study. The introduction of MXene (3.4 wt%) helped to reduce the recombination of photo-induced electrons and holes, and thus enhanced the photocatalytic activity by 30%. A continuous flow-through reactor loaded with the as-prepared photocatalyst coated onto polyurethane foam was developed to inactivate airborne bacteria. The photocatalytic inactivation efficiency of airborne Escherichia coli (E. coli) achieved 3.4 lg order under ultraviolet (UV) irradiation at 254 (UV254), which was superior to that using UV254-only treatment with 2.5 lg order under the same operating condition (95% relative humidity and retention time of 4.27 s). The effect of humidity and bacteria species on inactivation performance was also investigated. The thick cell membrane could protect bacteria from photocatalytic oxidation while high humidity increased the photocatalytic inactivation efficiency by generating more reactive oxygen species. The phenomena of photo reactivation and dark repair of airborne E. coli using UV254-only treatment was observed. However, no reactivation occurred after UV photocatalytic inactivation, and even a continuous decline under visible light. These results suggested a different inactivation mechanism between UV irradiation and UV photocatalysis that the former inactivated bacteria by damaging their DNA, whereas photocatalysis physically damaged their cell structure.