基于AC/SnO_2-Sb粒子电极的苯酚电催化氧化

Electrochemical oxidation of phenol on AC/SnO_2-Sb particle electrodes

采用热分解法,以活性炭(AC)颗粒为基体,利用Sn-Sb固溶特性制备具有催化活性的AC/Sn O2-Sb粒子电极,并通过N2吸附法、扫描电镜(SEM)、X射线衍射(XRD)及电化学测试对其微孔结构、微观形貌、物相组成和电催化活性进行表征。结果表明,Sn O2-Sb活性组分减少了AC介孔但未破坏高孔隙结构,且以固溶体形式广泛分布于AC孔道表面,不仅增强了AC孔隙内部降解有机物的活性,还增加了电催化活性位点,有助于提升催生羟基自由基的能力;同时只有AC/Sn O2-Sb粒子电极的循环伏安曲线(CV)在1.10V存在明显的苯酚氧化峰,说明Sn O2-Sb固溶体在电催化氧化的作用下,可直接参与苯酚的催化降解。以模拟苯酚废水考察粒子电极的电催化活性以及稳定性,结果表明,在电流密度12.0m A/cm2和反应时间3h条件下,AC/Sn O2-Sb粒子电极的COD和苯酚去除率分别为78.43%和79.52%,均高于AC粒子电极的去除率。此外,AC/Sn O2-Sb在30天连续水处理中表现出较好的电化学稳定性。

As Sn O2-Sb solid solution have excellent catalytic activity,a kind of AC/Sn O2-Sb particle electrodes was manufactured with thermal decomposition method. Nitrogen adsorption,scanning electron microscopy（SEM）,X-ray diffraction（XRD） and electrochemical test were used to analyze the surface area,porosity,phase composition,the crystal structure and electrocatalytic activity of modified activated carbon（AC）. The results showed that Sn O2-Sb as continuous solid solution reduced quantity of mesoporous structures but not damaged high porosity of AC that is beneficial to the electrocatalysis. In addition,these metal oxide coatings widely distributed in the channel of AC,which could improve not only electrical catalytic activity to ·OH but also the direct oxidation activity on the surface of the electrode. Meanwhile cyclic voltammetry curve of AC/Sn O2-Sb showed an obvious oxidation peak at 1.10 V,which indicated direct oxidation of phenol can occur at the surface of AC/Sn O2-Sb. Bulk electrolysis experiments with AC and AC/Sn O2-Sb were conducted with simulated phenol wastewater. The results indicated the removal of COD and phenol with AC/Sn O2-Sb（78.43% and 79.52%） were better than that of AC under 12.0m A/cm2 current density during 3h electrolysis.Moreover excellent electrochemical stability of AC/Sn O2- Sb can be shown in 30 days continuous water treatment.