MnO_2@Graphite电极类电Fenton降解有毒有机污染物

Degradation of Organic Pollutant by MnO_2@Graphite Electrode in Electro-Fenton-like System

制备了二氧化锰复合石墨(MnO2@graphite)电极,通过XRD,TEM对电极材料进行表征,并通过电化学工作系统(循环伏安法,线性扫描伏安法,计时电量法)对MnO2@graphite电极的电催化机理进行了研究。以有机染料罗丹明B(Rhodamine B,RhB)和2,4-二氯苯酚(2,4-DCP)为对象,探讨了pH7.0中性条件下其类电Fenton降解的电催化性能。对1.0×10-5 mol/LRhB在外加电压6 V和支持电解质Na2SO4 10g/L条件下,类电Fenton反应120 min,RhB降解率达100%。通过紫外-可见吸收光谱(UV-vis)、红外光谱、总有机碳(TOC)测定等方法,研究了类电Fenton体系深度氧化降解RhB特性。结果表明,4 h RhB矿化率可达67.6%,同样条件下,7 h 2,4-DCP矿化率达到84.9%。同时,采用辣根过氧化物酶催化反应吸光光度法和苯甲酸荧光分析法分别分析测定RhB降解反应过程中H2O2和羟基自由基(.OH)的量,表明有机物的降解涉及.OH历程。

A new electrode was synthesized by pressing MnO2 and graphite,detected by X-ray diffraction（XRD） and transmission electron microscopy（TEM）.Electrocatalytic mechanism of the electrode was studied by electrochemical work system such as cyclic voltammetry,linear sweep voltammetry and time power method.Electrocatalytic characteristics of electro-Fenton-like system in neutral pH（7.0） was studied by degrading organic dye Rhodamine B（RhB） and 2,4-dichlorophenol（2,4-DCP）.It was found that 100% degradation of 1.0×10-5 mol/L RhB was achieved in 120 min with applied voltage of 6 V and supporting electrolyte of 10 g/L NaSO4.The deep degradation process of RhB was studied by UV-visible spectrum（UV-vis）,IR and total organic carbon（TOC）.The findings showed that RhB and 2,4-DCP were degraded effectively with the mineralization ratio of RhB 67.6% at 4 h and DCP 84.9% at 7 h respectively.Meanwhile horseradish peroxidase（POD）and benzoic acid fluorescence analysis method were used to detect the concentration of hydrogen peroxide（H2O2）and hydrogen radicals（.OH）.The experiment results indicated that electrocatalysis degradation of organic matters referred to.OH radical mechanism.