核壳型纳米Au@Ag复合材料的制备、催化及光抑菌

Preparation,catalysis and photoinhibition of core-shell Au@Ag nanocomposites

以纳米Au为核,在其表面负载Ag合成核壳型纳米Au@Ag复合材料,利用TEM、EDX、UV-Vis对材料进行表征。以甲基橙为目标污染物研究材料的催化加氢活性,并初步探讨其催化机制;用革兰氏阴性菌大肠杆菌(E.coli)和革兰阳性菌金黄色葡萄球菌(S.aureus)为模式菌研究材料的光抑菌活性和抑菌机制。结果表明,相比纳米Ag,纳米Au@Ag在8 min内对甲基橙的降解率为99%以上,加氢产物为对氨基苯磺酸钠和对二氨基苯;抑菌实验证明:相比黑暗环境中,300 W光照下的纳米Au@Ag具有更强的抑菌性能,在浓度为300μg/mL,光照10 min下的抑菌效率更高,并对细菌的迟缓期和对数期的生长阶段作用较为明显,对E.coli的细胞壁破坏较为严重。

Core-shell nanoparticles Au@Ag composite is synthesized by loading Ag on the surface of nano-Au as the core.The properties of the Au@Ag coreshell NPs are characterized by TEM,EDX and UV-vis.The catalytic hydrogenation activity of the material is studied with methyl orange as the target pollutant,and its catalytic mechanism is preliminarily discussed.The photoinhibition activity and antibacterial mechanism of the bacteria are studied using Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)as the model bacteria.The results indicate that compared with nano-Ag,the degradation rate of nano-Au@Ag for methyl orange is more than 99%within 8 min,and the hydrogenation products are sodium p-aminobenzenesulfonate and p-diaminobenzene.The antibacterial experiments show that compared with the dark environment,the nano-Au@Ag under 300 W illumination had stronger antibacterial properties.At the concentration of 300μg/mL,the antibacterial efficiency is higher under the illumination of 8 min.The effect on the growth stages of bacterial retardation and logarithmic phase is obvious,and the cell wall of E.coli is seriously damaged.