磁性三乙烯四胺氧化石墨烯对Cu2+的吸附行为

为了提高氧化石墨烯(GO)的吸附能力和分离效果,采用恒温搅拌法和水热法制备磁性三乙烯四胺氧化石墨烯(M-T-GO)复合吸附剂。通过X射线衍射(XRD)、傅里叶红外光谱(FT-IR)和透射电镜(TEM)测试方法对其进行表征,并对M-T-GO对Cu²⁺的pH、吸附动力学、吸附等温线和吸附热力学进行研究。结果表明,M-T-GO对Cu²⁺的吸附符合二级反应动力学和Langmuir吸附等温式描述,吸附反应为自发吸热过程,饱和吸附量为245.09 mg·g^-1,同时具有快速分离和易再生的优点。采用X射线光电子能谱(XPS)推测M-T-GO对Cu²⁺的吸附机理,结果表明M-T-GO主要通过螯合作用和静电引力对Cu²⁺进行吸附。

Adsorption behavior of magnetic triethylene tetramine-graphene oxide nanocomposite for Cu2+

A novel composite adsorbent of magnetic triethylene tetramine graphene oxide (M-T-GO) was firstly prepared by isothermal stirring and hydrothermal method to improve adsorption ability and separation efficiency of graphene oxide (GO). M-T-GO was characterized by Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD) and transmission electron microscope (TEM), respectively. The pH, adsorption kinetics, isotherms and thermodynamics of Cu²⁺ on M-T-GO were studied, indicating that the adsorptions kinetic was well fitted by pseudo-second-order model and the equilibrium adsorption was well described with Langmuir model. The saturated adsorption capacity of Cu²⁺ was about 245.09 mg·g^-1 on M-T-GO. M-T-GO could make separation of the adsorbents easy in the foreign magnetic field and possess good performance of regeneration. The adsorption process of Cu²⁺ was spontaneous and endothermic by the calculated thermodynamic parameters. X-ray photoelectron spectroscopy (XPS) spectra suggested that Cu²⁺ was adsorbed on M-T-GO mainly through the chelation and electrostatic attraction.