摘要
电化学法通常较生物法更能高效处理难降解有机污染物;但其实用性取决于所采用的电极材料和电解过程的能耗。制备了一种新型的负载Pt-Bi的石墨烯-活性炭-聚四氟乙烯(PTEF)复合电极;并对其进行了表征和电化学性能测试。研究了电极对甲基橙电催化降解效果及其影响因素。结果表明:负载Pt-Bi后,电极电化学性能得到明显提高,其电极比电容增加了7%;甲基橙降解过程与准一级反应动力学模型较吻合,通入空气和施加方波电位均有利于甲基橙的去除;在甲基橙的电化学降解过程中,电催化起主要作用,对甲基橙降解的影响远大于电极自身的吸附作用。在方波电位、不通气体条件下,甲基橙初始浓度为20 mg/L时,电解180 min后甲基橙的去除率达到95.81%,交替进行的氧化还原反应有利于甲基橙的降解。为染料的高效降解提供了一种有效的方法,有望应用于废水中其他难降解有机污染物的处理。
Electrochemical methods were usually more efficient for the degradation of recalcitrant pollutants than biological approaches,but their treatment performance relies heavily on the applied electrode and the energy consumption. Here,a novel platimum-bismuth（ Pt-Bi） bimetallic graphene-activated carbon-PTEF composite nanostructured electrode was prepared,characterized,electrochemically tested,and used for the electrochemical degradation of methyl orange（ MO）. It was shown that the electrochemical performance of the electrode was improved obviously with 7% upgrade rate of its specific capacitance after loading platimum-bismuth bimetallic nanoparticles.MO degradation followed pseudo first-order kinetic equation,air exposure and square wave potential were both beneficial to the MO removal,the effect of electrocatalysis on the degradation of MO is much larger than that of adsorption of electrode itself. In the system,a high MO degradation of over 95. 81% was achieved within 180 min under non-aeration condition with MO initial concentration of 20 mg/L. The alternate oxidation and reduction processes both contributed to the degradation. This work offers an effective method for enhancing degradation of dyes and may hopefully be also applied for treatment of other recalcitrant compounds in water and wastewater.
出处
《科学技术与工程》
北大核心
2017年第34期159-165,共7页
Science Technology and Engineering
基金
上海市科委能力建设计划(122500500900)资助
关键词
Pt-Bi二元金属
活性炭
方波电位
电化学降解
platimum-bismuth bimetallic
activated carbon
square-wave potential
electrochemical degradation
