铝掺杂改性钛基PbO2电极性能研究

Properties of Al-doped titanium based PbO2 electrodes

摘要:

采用阳极电沉积技术制备了金属铝掺杂改性的Ti/PbO₂电极,通过表面粗糙度测量仪,扫描电镜,X射线衍射仪、线性极化扫描和交流阻抗谱电化学测试和加速寿命试验对铝掺杂引起PbO₂涂层电极的物理化学特性的影响进行分析,并对铝掺杂改性的Ti/PbO₂电极对苯酚模拟废水电催化氧化降解行为进行考察。结果表明,Al₃₊添加可使得Ti/PbO₂电极涂层结晶细化、沉积均匀致密,表面粗糙度明显降低,结瘤缺陷改善；铝掺杂改性的Ti/PbO₂析氧电位升高,电荷传递及催化性能提高,但呈非单调变化,其中添加3mM Al₃₊制备电极的析氧电位最高可达到2.09V,导电性优异,电催化性能最佳,电化学稳定性高,其强化寿命可达到460h,比未改性电极寿命提高了100h。铝掺杂改性的Ti/PbO₂电极对苯酚模拟废水具有良好的电化学氧化降解能力,180min处理后苯酚去除率最高可达到93.6%,COD去除率最大可达到73.6%。

Abstract:

Al-doped Ti/PbO₂ electrodes were prepared by using anodic deposition from solution containing Al (III) cation. Influence of Al-doping on the physicochemical properties of modified PbO₂ coating electrodes was characterized by surface roughometer, scanning electron microscope (SEM), X-ray diffraction (XRD), linear polarization and electrochemical impedance spectroscopy (EIS) techniques, and accelerated life test. The electrocatalytic oxidation degradation behavior of Al-doping PbO₂ electrodes for phenol simulation wastewater was compared. These results show that PbO₂ coatings with smaller size, uniform and dense surface, lower surface roughness and less nodulation defect are obtained when a certain amount of Al₃₊was added into the electrodeposition solution. Al-doping results in increased oxygen evolution potential, improved charge transfer capacity and enhanced electrocatalytic performance for PbO₂ electrodes. Nevertheless, those properties do not uniformly varied with increase of Al₃₊additive amount. When deposited 3h in the bath solution contain 3mM Al₃₊, the electrode prepared has maximum oxygen evolution potential 2.09 V, excellent electrical conductivity, the best electrocatalytic property and the longest accelerated life of 460 h, which is increased by 100h compared with that of the unmodified electrode. The Al-doped Ti/PbO₂ electrodes show good electrochemical oxidation degradation capacity for phenol simulated wastewater. After treatment 180 min the removal rate of phenol is up to 93.6%, and the maximum removal rate of COD can reach 73.6%.