研究报告

  • 贺君,陈思琦,唐首锋,高作宇,黄筱晗,宋来洲.MnO2/EGM电极制备及电化学降解罗丹明B的研究[J].环境科学学报,2020,40(11):3922-3930

  • MnO2/EGM电极制备及电化学降解罗丹明B的研究
  • Preparation of MnO2/EGM electrode and electrochemical degradation of Rhodamine B
  • 基金项目:国家自然科学基金青年科学基金(No.51608468)
  • 作者
  • 单位
  • 贺君
  • 燕山大学, 环境与化学工程学院, 秦皇岛 066004
  • 陈思琦
  • 燕山大学, 环境与化学工程学院, 秦皇岛 066004
  • 唐首锋
  • 燕山大学, 环境与化学工程学院, 秦皇岛 066004
  • 高作宇
  • 燕山大学, 环境与化学工程学院, 秦皇岛 066004
  • 黄筱晗
  • 燕山大学, 环境与化学工程学院, 秦皇岛 066004
  • 宋来洲
  • 燕山大学, 环境与化学工程学院, 秦皇岛 066004
  • 摘要:为开发高效的电化学阴极材料,提高溶解氧还原为H2O2的产率,利用电沉积法制备出了二氧化锰/膨胀石墨复合基(MnO2/EGM)电极,并用于罗丹明B(RHB)电化学阴极降解过程的研究.实验以纯石墨电极片为阳极,MnO2/EGM复合材料为阴极,分别考察了溶液初始pH值、电流密度、电解质浓度、RHB初始浓度和反应温度对RHB脱色效果的影响.结果表明:利用电沉积法在EGM电极表面均匀负载了MnO2涂层;在二维电极体系中,当初始pH值为2,电流密度为40 mA·cm-2,电解质浓度为0.15 mol·L-1,罗丹明B初始浓度为8 mg·L-1,反应体系温度为25℃时,RHB在电解30 min后达到最大脱色率为94.43%,且其降解过程符合一级反应动力学.运用循环伏安法(CV)研究了复合电极表面的电化学行为,以及在最佳降解条件下对H2O2浓度进行跟踪分析,并对降解机理进行了初步推测,发现电解液中的溶解氧在MnO2/EGM电极表面发生还原反应生成具有强氧化性的H2O2,破坏了RHB的发色基团,从而使罗丹明B达到脱色目的.
  • Abstract:In order to develop an efficient electrochemical cathode material and improve the yield of dissolved oxygen reduction to H2O2,a MnO2/EGM electrode was prepared by electrodeposition method,which was also used to degrade Rhodamine B (RHB).In this work,pure graphite electrode and MnO2/EGM electrode were used as the anode and the cathode,respectively,where the effects of the initial pH value,current density,electrolyte concentration,initial RHB concentration and reaction temperature on the decolorization of RHB were investigated.The as-obtained experimental results and conclusion were as follows: MnO2 was uniformly loaded on the surface of EGM electrode by electrodeposition method.When the initial pH was 2,the current density was 40 mA·cm-2,the electrolyte concentration was 0.15 mol·L-1,the initial concentration of RHB was 8 mg·L-1,and the temperature of the reaction system was 25 ℃ in the two-dimension electrode system,the decolorization rate of RHB reached 94.43% after 30 minutes of electrolysis,which accorded with first-order reaction kinetics.In addition,the degradation mechanism of RHB had been preliminary analyzed with the cyclic voltammetry (CV) method,which could be applied to investigate the electrochemical behavior of the composite electrode and the tracking analysis of H2O2 concentration under the best degradation conditions.It is found that the dissolved oxygen in the electrolyte could be reduced to H2O2 with strong oxidizing properties on the surface of the MnO2/EGM electrode,destroying the chromophores of RHB and achieving the purpose of decolorization of RHB.

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