稀土掺杂PbO_2电极的制备及催化性能研究

Preparation of PbO_2 Electrodes Bearing Rare Earth Metals and Its Catalytic Property

以SnCl4.5H2O,Sb2O3,La(NO3)3(或Nd(NO3))为前驱体(摩尔比分别为Sn∶Sb∶La(Nd)=100∶6∶(0.5,1,2),制备稀土(La,Nd)掺杂Sn,Sb溶胶,以钛电极为基体,用溶胶-凝胶法制备稀土(La,Nd)掺杂SnO2中间层,热处理温度为450和500℃,热处理时间共5 h;采用电沉积法制备PbO2表面层,得到改性PbO2阳极,优化了制备改性PbO2电极的稀土掺杂量。以含油污水为目标有机物,借助于CODCr去除情况分析电极的电催化氧化能力;分析了电极结构与电催化特性之间的关系。采用SEM和XRD分析了制备电极的表面形貌、晶体结构并通过电化学工作站对其析氧电位进行了表征分析。结果表明,中间层掺杂La元素的电极,掺杂比为Sn∶Sb∶La=100∶6∶1时电极性能最好;而中间层掺杂Nd元素,掺杂比为Sn∶Sb∶Nd=100∶6∶2时电极的性能最好,此比例时电极对目标有机物CODCr去除率分别为91.90%和90.93%。

With SnCl4· 5H2O, Sb2O3 and La（NO3）3 or Nd（NO3）3 as precursors [Sn ： Sb ： La（Nd） = 100 ： 6 ： （0.5, 1,2） ], the interlayer of Ti/SnO2-Sb2O3/PbO2 DSA electrodes bearing La or Nd were prepared by sol-gel method. The heat-treatment temperature was 450 and 500 ℃. The heat treatment time was totally 5 h. The surfaces of the electrodes were prepared by electrochemical deposition. Taking oily wastewater as model organics, the electro-catalytic characteristics of prepared anodes and the relationship between the electro-catalytic ability and the electrode structure were investigated by its removal rate of CODCr. The best doping amount of rare earth （La, Nd） was evaluated.The micrographs, crystal structure, the chemical environments of elements and element content of the interlayer and the surface layer of the electrodes were analyzed by SEM and XRD. The O2 evolution potential was observed by cyclic voltammetry. Under the condition of the experiment, the best proportion of doping amount was as follows： for the interlayer of La doping electrodes, the proportion was Sn ： Sb ： La = 100：6 ： 1 ; but for the interlayer of Nd-doped electrodes, the proportion was Sn ： Sb ： Nd = 100 ： 6 ： 2. At above proportion, the removal rate of CODCr of model organics were 91.90% and 90.93%, respectively.