摘要
在低温(200 oC)下采用一步水热分解CoFe_2O_4纳米粒子表面的镉二硫代氨基甲酸酯配合物制备了磁性CoFe_2O_4/Cd S纳米复合物,运用X射线衍射、红外光谱、扫描电镜、X射线能量散射谱、紫外-可见光谱、透射电镜(TEM)、N2吸附-脱附、X射线光电子能谱和振动样品磁强计对所制样品进行了表征.TEM结果表明,CoFe_2O_4/Cd S纳米复合物由几乎均一的约20nm球形纳米粒子组成.光吸收谱显示该样品的带隙为2.24 e V,很适合用于声/光催化降解有机污染物.在紫外光照射下评价了CoFe_2O_4/Cd S纳米复合物的声催化H_2O2辅助降解甲基蓝、罗丹明B和甲基橙反应活性.结果表明,该纳米复合物对这3种染料均表现出很好的声催化活性(5–9 min内完全降解).另外,比较实验结果表明,CoFe_2O_4/Cd S纳米复合物是一个比纯Cd S更高效的声催化剂.因此,纳米复合是一种非常好的提高Cd S声催化活性的手段.该CoFe_2O_4/Cd S纳米复合物表现出的磁性使其很容易从反应混合物中分离出来而重复使用.
A magnetic CoFe2O4/Cd S nanocomposite was prepared via one-step hydrothermal decomposition of cadmium diethanoldithiocarbamate complex on the surface of CoFe2O4 nanoparticles at a low temperature of 200 ℃.The nanocomposite was characterised by X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FT-IR）,scanning electron microscopy,energy-dispersive X-ray spectroscopy（EDX）,UV-visible spectroscopy,transmission electron microscopy（TEM）,N2 gas sorption analysis,X-ray photoelectron spectroscopy（XPS）,and vibrating sample magnetometry.The FT-IR,XRD,EDX and XPS results confirmed the formation of the CoFe2O4/Cd S nanocomposite.Based on the TEM analysis,the CoFe2O4/Cd S nanocomposite constituted nearly uniform,sphere-like nanoparticles of ～20 nm in size.The optical absorption spectrum of the CoFe2O4/Cd S nanocomposite displayed a band gap of 2.21 e V,which made it a suitable candidate for application in sono/photocatalytic degradation of organic pollutants.Accordingly,the sonocatalytic activity of the CoFe2O4/Cd S nanocomposite was evaluated towards the H2O2-assisted degradation of methylene blue,rhodamine B,and methyl orange under ultrasonic irradiation.The nanocomposite displayed excellent sonocatalytic activity towards the degradation of all dyes examined—the dyes were completely decomposed within 5–9 min.Furthermore,a comparison study revealed that the CoFe2O4/Cd S nanocomposite is a more efficient sonocatalyst than pure Cd S;thus,adopting the nanocomposite approach is an excellent means to improve the sonoactivity of Cd S.Moreover,the magnetic properties displayed by the CoFe2O4/Cd S nanocomposite allow easy retrieval of the catalyst from the reaction mixture for subsequent uses.
基金
the Lorestan University and Iran Nanotechnology Initiative Council (INIC) for their financial support
