含锡锑中间层的铅锑电极的制备及电催化性能研究

PREPARATION AND ELECTRO-CATALYTIC PERFORMANCE OF LEAD-ANTIMONY ELECTRODE WITH A TIN-ANTIMONY INTERMEDIATE LAYER

采用溶胶凝胶法制备得到具有高稳定性和高电催化活性的含锡锑中间层的铅锑电极,利用X射线衍射(XRD)、扫描电镜(SEM)、能量色散谱(EDS)、Brunauer-Emmett-Teller(BET)、线性伏安测试(LSV)及循环伏安测试(CV)等测试方法对制备电极的物相结构、表面形貌、元素组成、比表面积及电催化性能进行分析表征,并考察了不同铅锑电极对二(2-乙基己基)磷酸酯废水的电催化降解性能及其稳定性。结果表明:含锡锑中间层的铅锑电极涂层主要为焦绿石型复合氧化物(Pb_(3)Sb_(2)O_(8.47))_(6.4),中间层表面的较大粗糙度及致密结构有利于提高电极稳定性,活性层表面的蜂窝状微孔结构使电催化性能显著增加。LSV及CV测试表明:含锡锑中间层的铅锑电极具有较好的电催化活性及导电性;该电极在电解二(2-乙基己基)磷酸酯废水2 h的COD去除率可达到92.5%,连续使用62 h后COD去除率能维持在91%以上,电极加速寿命可达到30 h,换算成一般工业电流密度(0.1 A/cm^(2))下的电极实际使用寿命可达到5.5年。含锡锑中间层的铅锑电极具有优越的电催化活性及稳定性,在高盐有机废水处理中具有良好的应用前景。

In this paper,the lead-antimony electrode with the tin-antimony intermediate layer,with high stability and electrocatalytic activity,was prepared by sol-gel method.The crystal structure,surface morphology,element composition,specific surface area and electrocatalytic performance of the electrode were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy-dispersive spectroscopy(EDS),Brunauer-Emmett-Teller(BET),linear sweep voltammetry test(LSV)and cyclic voltammograms test(CV).The electrocatalytic degradation performance and stability of different lead-antimony electrodes were investigated by taking di(2-ethylhexyl)phosphate ester wastewater as the research object.The results indicated that the coating of the lead-antimony electrode with tin-antimony intermediate layer was mainly pyrochlore-type composite oxide,higher roughness and compact structure of the intermediate layer were beneficial to improve the stability of the electrode,and the honeycomb microporous structure of the active layer made electro-catalytic performance significantly increased.The LSV and CV test indicated that the lead-antimony electrode with tin-antimony intermediate layer has better electrocatalytic activity and electrical conductivity,the COD removal rate of the electrode reached 92.5%after 2 hours of electrolysis,and the numerical value could maintain above 91%after 62 hours of continuous operation.The accelerated life of the electrode was up to 30 hours,and its actual life could reach 5.5 years when the accelerated life was converted into the service life,under the condition of the general industrial current density of 0.1 A/cm^(2).The lead-antimony electrode with a tin-antimony intermediate layer has ideal electrocatalytic activity and stability,showing a good application prospect in the treatment of high-salt organic wastewater.