超声掺Bi二氧化铅电极电氧化降解2-氯苯酚研究

目的提高Pb O_2/Ti的使用寿命、对目标反应物的电氧化催化活性及选择性。方法以覆有Sn O_2+Sb_2O_3的Ti网为阳极,分别在Pb(NO_3)_2、Na F混合溶液及Pb(NO_3)_2、Na F、Bi(NO_3)_3组成的掺Bi混合溶液中,在电沉积液p H=2、60℃、电沉积电流密度为0.04 A/cm~2的条件下,进行常规电沉积及超声电沉积1 h,制备出Pb O_2/Sn O_2+Sb_2O_3/Ti,Bi-Pb O_2/Sn O_2+Sb_2O_3/Ti,Pb O_2(ultrasonic)/Sn O_2+Sb_2O_3/Ti,Bi-Pb O_2(ultrasonic)/Sn O_2+Sb_2O_3/Ti 4类二氧化铅电极。在硫酸溶液中测定其加速寿命,用稳态极化曲线分析电催化性及选择性,以2-氯苯酚的电氧化降解反应为模型反应,考察电解2-氯苯酚废水的处理效果,用X射线衍射仪和电子扫描电镜表征沉积层晶相和形貌。结果 Bi-Pb O_2(ultrasonic)/Sn O_2+Sb_2O_3/Ti的加速寿命比Pb O_2/Sn O_2+Sb_2O_3/Ti提高了54%。电氧化降解2-氯苯酚溶液4 h后,以掺Bi二氧化铅电极为阳极,相比于二氧化铅电极,对2-氯苯酚的脱除率提高了19%,槽压降低了7%,稳态极化曲线和电氧化降解2-氯苯酚溶液试验反映了相同的结论。结论超声波环境和Bi掺杂显著提升电极的性能,掺Bi的二氧化铅沉积层表现出较高的电催化性和电氧化2-氯苯酚的选择性,超声电沉积二氧化铅能增大电极比表面积,提高电极的表观催化活性和电极加速寿命。

Electro-catalytic Oxidation of 2-chlorophenol on a Ultrasonic Doped Bi-PbO2 / Ti in Aqueous Solution

Objective To improve the service life, electrocatalytic activity, electrocatalytic selectivity of the Ti-base lead diox-ide electrode for the target pollutant of 2-chlorophenol. Methods In this paper, four different types of Ti-base lead dioxide eletrodes including PbO2/SnO2+Sb2O3/Ti,Bi-PbO2/SnO2+Sb2O3/Ti,PbO2(ultrasonic)/SnO2+Sb2O3/Ti and Bi-PbO2(ultrasonic)/SnO2+Sb2 O3/Ti were prepared by electro-deposition and ultrasonic-associated electro-deposition using Ti web with an SnO2+Sb2 O3 layer obtained by spreading and oxidating polymeric precursor as anodes. The composition of the electrolyte and operating conditions were as follows. The mixed solution of NaF and Pb( NO3 ) 2 or the mixed solution of NaF, Pb( NO3 ) 2 and Bi( NO3 ) 3 was used. The pH of the mixed solution was 2, the coating current density was 0. 04 A/cm2 , the temperature of coating solution was 60 ℃, and the time of electro-deposition was 1 hour. The accelerated service life was determined in sulfuric acid solution. Their electric catalysis and electro catalytic selectivity were analyzed by static anodic polarization curves, the effect of electrolysing 2-chlorphenol solution was tested using the electro-oxidative degradation of 2-chlorophenol as the model response, the morphology and crystal phase of sur-face coating was characterized by scanning electron microscopy and X-ray diffraction. Results The accelerated life of Bi-PbO2( ul-trasonic)/SnO2+Sb2 O3/Ti increased by 54% than PbO2/SnO2+Sb2 O3/Ti. Compared to PbO2/SnO2+Sb2 O3/Ti, the 2-chlorophe-nol removal rate had a 19% increase after 4 hours of electrolysis using Bi-PbO2( ultrasonic)/SnO2+Sb2 O3/Ti as an anode, and the electrolyzer voltage had a 7% reduction. The static anodic polarization curves and the electro-oxidative degradation test of 2-chloro-phenol solution showed the same results. Conclusion Ultrasonic environment in the process of preparation of electrode and doped Bi have a beneficial effect on the performance. Compared with non-doped electrode, the bismuth-doped electrode′s electro-catalytic property and electro-catalytic selectivity for the degradation of 2-chlorphenol is better, and its specific area is larger, its apparent catalytic activity is better, its life is longer by ultrasonic-associated electro-deposition than by electro-deposition.