薄层大面积自支撑碳纳米管电极材料的电容脱盐性能

Self-supporting Macroscopic Carbon Nanotubes Microfiber Hybrid Electrodes for Capacitive Deionization

以具有三维开放网络结构的烧结8μm-Ni金属纤维(SMF-Ni)为基底,通过乙烯催化化学气相沉积法在金属纤维表面生长碳纳米管(CNTs),制备了以金属Ni纤维网络为集流极、CNTs为离子存储库,尺度跨越宏观、介观和纳米的自支撑薄层大面积CNTs/SMF-Ni(CNTs质量分数为50%)复合电极材料.用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱(FTIR)、N2吸附、脱附等温线和X射线衍射(XRD)等方法对电极材料进行了表征,并考察了其作为电极对质量分数为0.01%的NaCl水溶液的电容脱盐性能.自支撑CNTs/SMF-Ni复合电极材料由于具有优异的离子传导和表面电荷传递性能以及较大的介孔表面积,在1.2 V的工作电压和5 mL/min的水溶液流速下,对NaCl的电吸附容量和脱盐率分别达159μmol/gCNTs和57%.用H2O2对CNTs/SMF-Ni电极材料进行氧化处理后,CNTs表面含氧基团的大量增加增大了材料的亲水性,从而进一步提升了该复合材料的电容脱盐性能.

A promising self-supporting macroscopic carbon nanotubes（CNTs） electrode was prepared by catalytic chemical vapor deposition method through CNTs growth on a three-dimensional network of sinter-locked conductive 8 μm-nickel fibers,namely CNTs/SMF-Ni（CNTs mass fraction 50%）,in which the Ni-microfibrous network serves as current collector and CNTs as ion storage reservoir.This approach permits the desirable large area fabrication and unique combinations of binderlessness,excellent thermal/electrical conductivity,macro-/meso-sized hierarchical porous structure,and individual/uniform dispersion of CNTs.This CNTs electrode was characterized by scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,Fourier transform infared spectrometry（FTIR）,N2 isothermal adsorption-desorption and X-ray diffraction.The desalination performance for 0.01%NaCl aqueous solution was tested using the CNTs/SMF-Ni as the electrodes of the capacitive deionization.Owing to the excellent ion diffusivity,high conductivity and high mesopore surface area,such hybrid electrodes delivered the maximum electrosorption capacity of 159 μmol/g CNTs with a salt removal rate of 57%,using the direct current voltage of 1.2 V and water flow rate of 5 mL/min.The desalination performance of such hybrid electrodes could be further promoted by oxidation treatment using H2O2 solution,due to significantly enhanced hydrophilicity stemmed from formation of large amount of O-containing groups on the CNTs surface.