铝掺杂改性钛基PbO2电极性能研究

Properties of Al-doped Titanium Based PbO2 Electrodes

采用阳极电沉积技术制备了金属铝掺杂改性的钛基PbO2电极。通过表面粗糙度测量,扫描电镜、X射线衍射结构分析,线性极化和交流阻抗谱电化学测试和加速寿命试验分析了铝掺杂对PbO2涂层电极的物理化学特性的影响并考察了铝掺杂PbO2电极对苯酚模拟废水的电催化氧化降解行为。结果表明,Al3+添加可使得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PbO2电极析氧电位升高,电荷传递及催化性能提高,但呈非单调变化,其中添加3 mmol/L Al^3+制备电极的析氧电位最高,可达2.09 V,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460 h,比未掺杂电极寿命提高了100 h。铝掺杂改性的PbO2电极对苯酚模拟废水具有良好的降解能力,180 min处理后苯酚去除率最高可达94%,COD去除率最大可达73.6%。

Al-doped Ti/PbO2 electrodes were prepared by 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.The results show that PbO2 coatings with smaller grain size,uniform and dense surface,lower surface roughness and less nodulation defect are obtained when a certain amount of Al3+is added into the electrodeposition solution.Al-doping results in the increase of oxygen evolution potential,improvement of charge transfer capacity and enhancement of electrocatalytic performance for PbO2electrodes.Nevertheless,these properties do not uniformly vary with increase of Al3+addition amount.When deposited for 3 h in the bath solution containing 3 mmol/L Al^3+,the prepared electrode has maximum oxygen evolution potential 2.09 V,excellent electrical conductivity,the best electrocatalytic property and the longest accelerated life of 460 h.The Al-doped Ti/PbO2 electrodes show excellent electrochemical oxidation degradation capacity for phenol simulated wastewater.After treatment for 180 min the removal rate of phenol is up to 94%,and the maximum removal rate of COD can reach 73.6%.