新型析氧阳极制备及性能研究

发布时间：2018-11-12 11:30

【摘要】：工业锌电积过程广泛采用Pb-Ag合金作阳极,其具有制作成本低廉、可形成Pb02保护层等优势,但存在析氧过电位高、易弯曲变形等不足。因此,有必要研制电催化活性和稳定性更优的新型析氧阳极。论文首先对Pb-Ag (0.3wt.%)阳极在Mn(CH3COO)2溶液中电沉积MnO2进行了热力学分析,考察了沉积电位、Mn(CH3COO)2浓度对Pb-Ag阳极性能的影响,在此基础上制备出MnO2活化Pb-Ag阳极,并通过X射线衍射(XRD)、扫描电镜(SEM)、X荧光分析(XRF)等对Mn02活化Pb-Ag日极表层进行表征。此外,利用粉末冶金技术制备出碳纳米管增强铅基复合阳极(Pb-CNTs阳极),对其电化学性能和表面硬度进行了检测,同时将其与纯铅阳极作比较。研究表明, Pb-Ag阳极置于Mn(CH3COO)2溶液中进行电沉积,增加Mn(CH3COO)2浓度和沉积电位,阳极电催化活性先升高后降低,表面硬度则随之增加；在Mn(CH3COO)2浓度0.05 mol/L、沉积电位1.15V下,制备得到的MnO2活化Pb-Ag阳极具有良好的电催化活性和电化学稳定性,其析氧过电位较Pb-Ag阳极降低约0.2V(电流密度为0.05A/cmm2),表面硬度较Pb-Ag阳极提高65.9%。Pb-CNTs阳极制备过程中,确定出铅-碳纳米管复合粉末(Pb-CNTs粉末)的最佳制备工艺条件：超声功率120W、Pb(CH3COO)2浓度0.005mol/L、CH3COOH浓度2.1mol/L、试剂A浓度0.6mol/L、明胶浓度2.0g/L、SDBS浓度0.5g/L、碳纳米管含量0.5g/L,分散1h,施加阴极电流密度0.30A/cm2,室温沉积1h；制备得到的Pb-CNTs阳极析氧过电位较纯铅阳极降低约0.2V(电流密度为0.05A/cm2),表面硬度是纯铅阳极的3.93倍。
[Abstract]:Pb-Ag alloy is widely used as anode in industrial zinc electrodeposition process, which has the advantages of low cost and Pb02 protective layer, but it has some disadvantages such as high oxygen evolution overpotential, easy bending deformation and so on. Therefore, it is necessary to develop a new oxygen evolution anode with better electrocatalytic activity and stability. Firstly, the thermodynamics analysis of Pb-Ag (0.3wt.%) anode electrodeposition MnO2 in Mn (CH3COO) 2 solution was carried out, and the effect of the concentration of, Mn (CH3COO 2 on the anodic properties of Pb-Ag was investigated. On this basis, MnO2 activated Pb-Ag anode was prepared, and the surface layer of Pb-Ag dipole activated by Mn02 was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), X fluorescence analysis (XRF) et al. In addition, carbon nanotube reinforced lead based composite anode (Pb-CNTs anode) was prepared by powder metallurgy technology. The electrochemical properties and surface hardness of the anode were measured and compared with pure lead anode. The results show that the electrodeposition of Pb-Ag anode in Mn (CH3COO) 2 solution increases the concentration and potential of Mn (CH3COO) 2, increases the electrocatalytic activity of the anode and then decreases the surface hardness. At Mn (CH3COO) 2 concentration 0.05 mol/L, deposition potential 1.15V, the prepared MnO2 activated Pb-Ag anode has good electrocatalytic activity and electrochemical stability. The oxygen evolution overpotential is about 0.2 V lower than that of Pb-Ag anode (current density is 0.05A/cmm2), and the surface hardness is higher than that of Pb-Ag anode during the preparation of 65.9%.Pb-CNTs anode. The optimum preparation conditions of lead-carbon nanotube composite powder (Pb-CNTs powder) were determined as follows: ultrasonic power 120WN Pb (CH3COO) 2 0.005mol / L CH3COOH 2.1mol / L, reagent A 0.6mol / L. Gelatin concentration 2.0 g / L SDBS concentration 0.5 g / L, carbon nanotube content 0.5 g / L, dispersion 1 h, cathodic current density 0.30 A / cm 2, room temperature deposition 1 h; The oxygen evolution overpotential of Pb-CNTs anode is about 0.2 V (current density is 0.05A/cm2) lower than that of pure lead anode, and the surface hardness is 3.93 times higher than that of pure lead anode.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ153;O646.54

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