纳米硒化银的生物合成及其对染料的吸附去除

Biosynthesis of Ag_2Se nanoparticles and the adsorption for dye molecules

利用菌株Pantoea sp.IMH实现了硒化银纳米颗粒的生物合成,同时,结合高分辨透射电镜(HRTEM)、能谱成像(EDX-mapping)、X射线粉末衍射(XRD)等多种表征手段对硒化银纳米颗粒进行了表征分析.结果表明,所合成的硒化银纳米颗粒的粒径为10~20 nm,其纳米颗粒的晶面间距为0.225 nm,对应于Ag2Se的(031)晶面.所合成的纳米颗粒的衍射环对应的标准Ag2Se晶面为(013)、(031)和(113)面.XRD结果表明,纳米颗粒的晶面为(111)、(112)和(004)晶面,说明菌株IMH能够合成纳米硒化银晶体.通过以不同电性的染料分子亚甲基蓝(阳性)、日落黄(阴性)、靛蓝(中性)作为目标分子进行吸附去除应用探索,发现硒化银纳米颗粒对阳性和中性染料分子有良好的吸附去除效果.这是由于硒化银纳米颗粒表面带有负电荷(Zeta电位分别为-11.8 m V(p H=5)、-13.0 m V(p H=7)、-13.0 m V(p H=9)).本研究为硒化银纳米颗粒的生物合成提供了新思路,拓展了硒化银纳米颗粒的合成方法.

Ag2 Se nanoparticles（ NPs） were biosynthesized by Pantoea sp. IMH. Multiple techniques,including high-resolution transmission electron microscope（ HRTEM）,energy-dispersive X-ray mapping（ EDX-mapping） and X-ray diffraction（ XRD）,were used to identify and characterize the NPs.The size of Ag2 Se NPs is 10 ～ 20 nm,and the lattice fringe spacing is 0.225 nm,corresponding to the（ 031） crystal surface of Ag2 Se. The selected area electron diffraction resolved the Scherrer ring patterns of（ 013）,（ 031）,and（ 113）. The characteristic XRD peaks were assigned to（ 111）,（ 112）,and（ 004） of Ag2 Se NPs. Ag2 Se NPs were used to adsorb different charged dye molecules including methylene blue,sunset yellow,and indigo. The results show that Ag2 Se NPs are effective in removing cationic and neutral molecules from water. The zeta potentials of Ag2 Se NPs were-11.8 m V at pH 5,-13.0 m V at pH 7,and-13.0 m V at pH 9,suggesting the negatively charged NPs preferentially adsorb positively and neutrally charged dye molecules. Our study provides a new one-step green biosynthesis of Ag2 Se NPs.