NF/PDMA/MnO_(2)-Co电容电极对低浓度Pb^(2+)的电吸附特性

Electrosorption Characteristics of NF/PDMA/MnO_(2)-Co Capacitor Electrode for Pb^(2+) in a Dilute Solution of Lead Ions

在泡沫镍基体上进行阳极电沉积制备了NF/PDMA/MnO_(2)-Co电极,使用FESEM-EDS、XPS和Raman谱、循环伏安和电容吸脱附测试等手段表征了复合电极的结构和评价其电容特性和对Pb^(2+)的吸附行为。结果表明,在电流密度为1 mA/cm^(2)、30℃和3 min条件下制备的NF/PDMA/MnO_(2)-Co复合电极,在Pb^(2+)浓度为20 mg/L的模拟废水中有比较高的比电容值(208.8 F/g),对Pb^(2+)有较高的吸附容量(59.9 mg/g);PDMA底层与Co掺杂MnO_(2)表层的协同作用提高了MnO_(2)电极电容和吸附性能;吸附动力学拟合表明,复合电极的吸附过程受物理、化学吸附混合控制,并受离子传质和孔隙内扩散的限制;电极的稳定性好,4次循环吸附后的吸附量仍达到51.7 mg/g。

NF/PDMA/MnO_(2)-Co electrode was prepared by anodic electrodeposition on the foam nickel substrate,and which then was characterized by FESEM-EDS,XPS and Raman spectroscopy.The capacitance characteristics and Pb^(2+)adsorption behavior of the composite electrode were evaluated by cyclic voltammetry and capacitance adsorption desorption tests.The results show that the NF/PDMA/MnO_(2)-Co composite electrode prepared by applied current density of 1 m A/cm^(2) at 30℃ for 3 min has a higher adsorption capacity(59.9 mg/g)and specific capacitance(208.8 F/g)for the simulated wastewater of 20 mg/L Pb^(2+).The synergistic effect of the bottom layer of PDMA and the top layer of Co doped MnO_(2) can effectively improve the capacitance and adsorption performance of the MnO_(2) electrode.The adsorption kinetics fitting shows that the adsorption process is controlled by the mixture of physical and chemical adsorption,and is limited by the mass transfer of ions and the diffusion in pores.The stability of the electrode is higher,and its adsorption capacity is 51.7 mg/g after four cycles of adsorption.