Visible-light-driven inactivation of Escherichia coli K-12 over thermal treated natural pyrrhotite
Visible-light-driven inactivation of Escherichia coli K-12 over thermal treated natural pyrrhotite
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DOI：
10.1016/j.apcatb.2015.04.024
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发表时间：
2015-10
影响因子：
22.1
通讯作者：
D. Xia;Yan Li;Guocheng Huang;Chi Fung Brian Fong;T. An;Guiying Li;H. Yip;Hunjun Zhao;Anhuai Lu-Anh
中科院分区：
文献类型：
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作者：
D. Xia;Yan Li;Guocheng Huang;Chi Fung Brian Fong;T. An;Guiying Li;H. Yip;Hunjun Zhao;Anhuai Lu-Anh
采用热处理方法对磁性天然磁黄铁矿（NP）矿物进行改性，制备了磁性NP矿物光催化剂.通过可见光下对大肠杆菌K-12的光催化灭活，评价了它们的光催化活性。与NP相比，发现退火的NP表现出显著增强的杀菌活性。其中，600 °C空气中处理的NP（NP 600）活性最高，失活率比未处理的NP提高近3倍。X射线衍射（XRD）分析表明，NP 600的矿物相转变为赤铁矿-黄铁矿（Fe 2 O3-FeS 2）混合微晶相。因此，其光催化性能的提高主要是由于形成了由赤铁矿和黄铁矿组成的Z-型络合物体系，提高了电子-空穴分离效率和杀菌效率。清除剂研究表明，主要杀菌剂从NP的超氧自由基（自由基dotO 2 −）变为NP 600的羟基自由基（自由基dotOH）。此外，振动取样磁化器（VSM）分析表明，热退火后的NP的饱和磁性增强。热处理后的纳米粒子的强磁性使得光催化剂在液相反应后的磁性恢复成为可能。此外，NP 600比未处理的NP更稳定，并且即使在四个反应循环之后也具有较低的金属离子泄漏。本研究为拓展天然矿物在水消毒中的应用领域提供了一种高性价比的天然矿物光催化剂和有效的改性策略。
A novel magnetic natural pyrrhotite (NP) mineral photocatalyst was developed and modified by thermal treatment. Their photocatalytic activity were evaluated by photocatalytic inactivation ofEscherichia coliK-12 under visible light. As compared to NP, the annealed NP was found to exhibit a remarkable enhanced bactericidal activity. Among them, the NP treated at 600 °C in air (NP600) had the highest activity and the inactivation rate was nearly 3 times higher than that of untreated NP. The X-ray diffraction (XRD) spectra indicated the mineral phase of NP600 transformed to mixed crystallite phases of hematite-pyrite (Fe2O3–FeS2) composite. Thus, the enhanced photocatalytic performance was mainly attributed to the formation of Z-scheme photocatalysis system composed of hematite and pyrite, which could improve the electron-hole separation efficiency and the bactericidal efficiency. Scavenger study demonstrated that the dominant bactericidal agent changed from superoxide radical (radical dotO2−) for NP to hydroxyl radical (radical dotOH) for NP600. Moreover, vibrating sampling magnetizer (VSM) analysis revealed that the saturated magnetism of NP after thermal anneal was enhanced. The strong magnetic behavior of thermal treated NP enabled the magnetic recovery of photocatalysts after liquid phase reaction. In addition, NP600 was more stable than untreated NP and with lower metal ion leakage even after four reaction cycles. This work supplied a cost-effective natural mineral-based photocatalyst and an efficient modification strategy to extend the application field of natural minerals in water disinfection.