Coarsening of extracellularly biosynthesized cadmium crystal particles induced by thioacetamide in solution.
Coarsening of extracellularly biosynthesized cadmium crystal particles induced by thioacetamide in solution.
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DOI：
10.1016/j.chemosphere.2011.03.063
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发表时间：
2011-05
期刊：
影响因子：
8.8
通讯作者：
Gui-qiu Chen;Zhengjun Zou;G. Zeng;Ming Yan;Jia-Qi Fan;Anwei Chen;Fan Yang;Wen-Juan Zhang;Liang Wang
中科院分区：
文献类型：
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作者：
Gui-qiu Chen;Zhengjun Zou;G. Zeng;Ming Yan;Jia-Qi Fan;Anwei Chen;Fan Yang;Wen-Juan Zhang;Liang Wang
首次研究了细胞外生物合成镉纳米晶体的一种新的粗化途径。利用白腐菌对镉离子进行吸附，合成细胞外镉晶体颗粒。在一定条件下，硫乙酰胺诱导颗粒粗化。扫描电镜显示，形成的镉晶体颗粒从100 nm左右粗化到2 ~ 3 μm。相应的能量色散x射线光谱证实了粒子中蛋白质的存在。随着粗化过程的完成，生物质对Cd（II）的最大去除率从17%提高到87%，相应的吸附量从4 mg g−1提高到24 mg g−1。用x射线衍射仪（XRD）和透射电镜（TEM）对粗化颗粒的性质进行了研究。对嵌入粗化颗粒的真菌菌丝球进行XRD分析，证实了立方结晶硫化镉颗粒的形成。TEM结果表明，粗化颗粒是由多个较小颗粒的团簇组成。利用傅里叶变换红外光谱研究了生物质表面官能团的变化。在此基础上，讨论了镉晶体颗粒形成和粗化的可能机理。
A novel coarsening route for extracellularly biosynthesized cadmium nanocrystals was investigated for the first time. In this process, the white rot fungusCoriolus versicolorwas employed to take up cadmium ions and synthesize extracellular cadmium crystal particles. The coarsening of the particles was induced by thioacetamide under certain conditions. Scanning electron microscopy showed that the formed cadmium crystal particles were coarsened from about 100 nm to 2–3 μm. The corresponding energy-dispersive X-ray spectra confirmed the presence of proteins in the particles. The maximum removal efficiency of Cd(II) increased from 17% to 87%, and the corresponding sorption capacity of biomass increased from 4 to 24 mg g−1with the completion of the coarsening process. The properties of the coarsened particles were also examined using X-ray diffraction (XRD) and transmission electron microscopy (TEM). XRD analysis of fungal mycelial pellets embedded with the coarsened particles confirmed the formation of cubic crystalline cadmium sulfide particles. The TEM results suggest that the coarsened particles were composed of clusters of several smaller particles. The changes in the functional groups on the biomass surface were studied through Fourier transform infrared spectroscopy. Based on the results above, a possible mechanism for the formation and coarsening of cadmium crystal particle is also discussed.