Role of anode material on the electrochemical oxidation of methyl orange
Role of anode material on the electrochemical oxidation of methyl orange
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DOI：
10.1007/s10008-015-2928-2
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发表时间：
2015-10-01
影响因子：
2.5
通讯作者：
Panizza, Marco
中科院分区：
文献类型：
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作者：
Labiadh, Lazhar;Barbucci, Antonio;Panizza, Marco
采用循环伏安法和本体电解法研究了Ti-Ru-Sn三元氧化物、二氧化铅和掺硼金刚石（BDD）、玻碳（GC）和金等电极材料对甲基橙子（MO，5-（4-硝基苯偶氮）水杨酸）的阳极氧化。伏安法的结果表明，与所有的电极材料，在析氧前的电位区域，MO的氧化涉及简单的电极转移，产生的聚合物膜，使电极表面失活，证实了傅立叶变换红外反射-吸收光谱（FTIRRAS）分析。在水分解区域的电极之间观察到非常不同的行为。虽然BDD和PbO 2恢复其初始活性的简单极化在2.3 V与饱和甘汞电极（SCE）由于产生大量的羟基自由基，破坏聚合物膜，TiRuSnO 2，GC和金不能完全重新激活，因为它们有一个低过电位的析氧，这种二次反应是有利于聚合物矿化。本体电解的结果表明，在10 mA cm（-2）极化3 h后，仅用BDD阳极就能完全去除色度和化学需氧量（COD）。使用PbO 2 MO被氧化，但残留的COD仍然在溶液中，而TiRuSnO 2只允许部分氧化MO。
The anodic oxidation of methyl orange (MO, 5-(4-nitrophenylazo)salicylic acid) has been studied by cyclic voltammetry and bulk electrolysis, using a range of electrode materials such as Ti-Ru-Sn ternary oxide, lead dioxide and boron-doped diamond (BDD), glassy carbon (GC) and gold anodes. The results of voltammetries show that with all the electrode materials, in the potential region before oxygen evolution, the oxidation of MO involves simple electrode transfer that produces a polymeric film that deactivates the electrode surface, as confirmed by Fourier Transform Infrared Reflection-Absorption Spectroscopy (FTIRRAS) analysis. A very different behaviour was observed among the electrodes in the region of water decomposition. While BDD and PbO2 regained their initial activity by simple polarisation at 2.3 V vs. saturated calomel electrode (SCE) due to the production of high amount of hydroxyl radicals that destroy the polymeric film, TiRuSnO2, GC and gold cannot be completely reactivated, because they have a low overpotential for oxygen evolution, and this secondary reaction is favoured over polymer mineralization. The results of bulk electrolysis showed that after 3 h of polarisation at 10 mA cm(-2), complete colour and chemical oxygen demand (COD) removal were obtained only with BDD anode. Using PbO2 MO was oxidised but a residual COD remains in the solution, while TiRuSnO2 permitted only a partial oxidation of MO.