钛基PbO2电极上苯酚的电化学氧化

Electrochemical Oxidation of Phenol on Ti-Based PbO2 Electrodes

摘要:

以Ti为基体，通过热分解Pb（NO3）2水溶液制备了Ti／PbO2电极以及含有SnO2＋Sb2O3中间层的Ti／SnO2＋Sb2O3／PbO2电极，并将所制备的电极应用于模拟苯酚废水的电化学氧化降解。结果表明：含有SnO2＋Sb2O3中间层的Ti／SnO2＋Sb2O3／PbO2电极在相同的操作电流密度下，槽电压低于未加中间层的Ti／PbO2电极。以聚合前驱体制得的Ti／SnO2＋Sb2O3／PbO2电极为阳极时，在25℃，电流密度15mA／cm^2下，恒电流电解浓度为2．13×10^-3mol／L的模拟苯酚废水，电解3．0h后，苯酚浓度降为1．67×10^-5mol／L，苯酚去除率达99．2％；电解6．5h后，COD下降率为84.3％。阳极寿命快速检测实验结果表明，添加锡锑中间层后的Ti／SnO2＋Sb2O3／PbO2电极，其寿命显著提高。

Abstract:

Three kinds of Ti-based PbO2 electrodes with or without SnO2+Sb2O3 interlayers were prepared by the thermal decomposition of Pb(NO3)2 solution and applied as anodes to simulate the electrolytic degradation process of phenol in aqueous solution. The experimental results show that the cell voltages for the anodes with the interlayers are lower than that without the interlayers. There are little differences in the removal rate of phenol, the COD values and the instantaneous current efficiency for the three kinds of electrode. The phenol removal rate reaches 99.2% after degradation process for 3.0 h, and the COD value declines to15.7% after degradation process for 6.5 h for the Ti/SnO2+Sb2O3/PbO2 electrode obtained by a polymeric precursor method as an anode. The instantaneous current efficiencies of electrolysis process for the three kinds of electrodes decrease with increasing the electrolysis time. The electrocatalytic activity and the accelerated lifetime were assessed by cyclic voltammetry and accelerated life tests for the three kinds of anodes. It has been found that the accelerated lifetime and electrocatalytic activity of the electrodes with SnO2+Sb2O3 interlayer are improved obviously.