• 关键词：亚甲基蓝染料  PO₄^3--MEO/Co(Ⅱ)电催化体系  氧化性中间产物  催化降解效果  电催化氧化机理

• 基金项目：国家自然科学基金（No.51108094，51378129）；广东省自然科学基金（No.2017A030313321，2015A030313494）；广东省高教厅-普通高校特色创新类项目（No.2016KTSCX035）

• 李冬梅
• 广东工业大学土木与交通工程学院, 广州 510006

• 张权
• 广东工业大学土木与交通工程学院, 广州 510006

• 喻子真
• 广州亚加达国际预科, 广州 511458

• 梁奕聪
• 广东工业大学土木与交通工程学院, 广州 510006

• 冯力
• 广东工业大学土木与交通工程学院, 广州 510006

• 李栩灏
• 广东工业大学土木与交通工程学院, 广州 510006

• 李绍秀
• 广东工业大学土木与交通工程学院, 广州 510006

• 摘要：以阳离子型染料亚甲基蓝（MB）废水为研究对象，采用钴介体电催化（MEO/Co（Ⅱ））与PO₄^3-协同作用体系（简称PO₄^3--MEO/Co（Ⅱ）体系），进行MB电催化降解实验，研究Co²⁺浓度、电流密度、pH值、电解质浓度等因素对PO₄^3--MEO/Co（Ⅱ）体系电催化降解MB的效果，并对其分解产物及机理进行了分析与探讨.结果表明：①PO₄^3--MEO/Co（Ⅱ）体系主要的氧化性中间产物为Co³⁺，同时存在少量羟基自由基及过磷酸盐.②PO₄^3-与MEO/Co（Ⅱ）体系之间具有明显的协同催化作用.PO₄^3--MEO/Co（Ⅱ）体系在40 min内对MB的降解率高达100%，是钴介电体系降解率的1.2倍，直接电化学氧化体系降解率的5倍.③Co²⁺浓度、电流密度及pH值对PO₄^3--MEO/Co（Ⅱ）体系氧化性能影响较大，而PO₄^3-浓度、电解质浓度对PO₄^3--MEO/Co（Ⅱ）体系的氧化性能影响较小.④PO₄^3--MEO/Co（Ⅱ）体系对MB的降解过程为：先从MB分子的N—C连接处断键，形成吩噻嗪、2-氨基-5-（N-甲基甲酰胺）苯磺酸及N¹，N¹-二甲基-1，4二氨苯等物质；然后将其降解为苯胺、苯酚、苯磺酸等；最终分解成CO₂和水等无机物.⑤PO₄^3--MEO/Co（Ⅱ）体系对MB的降解机理为：通过铂钛电极直接电催化，以及Co³⁺、过磷酸根、羟基自由基的间接氧化，其中，起主导作用的是Co³⁺的电催化氧化.

• Abstract：To take cationic dye methylene blue (MB) wastewater as an example to conduct electrocatalysis degradation experiments by using synergy reaction system of PO₄^3- and cobalt ions electrocatalysis (MEO/Co(Ⅱ) system) (for short: PO₄^3--MEO/Co(Ⅱ)) system).This study investigated the electrocatalysis degradation effect of PO₄^3--MEO/Co(Ⅱ) system on MB under different conditions by changing the factors below: Co²⁺ concentration, current density, pH value, concentration of electrolyte and etc.. In the meantime, the degradation products and the breakdown mechanism were discussed. The results showed that ① The main oxidizing intermediate products were Co³⁺ ions, and a small amount of hydroxyl radicals and phosphate existing in the PO₄^3--MEO/Co(Ⅱ) system. ②There was an obvious synergistic catalytic role happening in PO₄^3- and MEO/Co(Ⅱ) system. The degradation rate of PO₄^3--MEO/Co(Ⅱ) system on MB within 40 minutes was as high as 100%. Its degradation rate was five times that of the direct electrocatalysis oxidation system and 1.2 times that of MEO/Co(Ⅱ) system.③ The concentration of cobalt ion, current density and pH value had a great impact on oxidation performance in the PO₄^3--MEO/Co(Ⅱ) system. While the impact of the concentration of PO₄^3- and electrolyte on oxidation performance was relatively weaker. ④ The possible degradation process of MB in the PO₄^3--MEO/Co(Ⅱ) system was as follows: Firstly, the bond in the N—C junction of the MB molecule was broken and intermediate substances were produced, such as phenothiazine, 2-amino-5-(N-methyl formamide) benzene sulfonic acid and N¹,N¹- dimethyl-1,4 diaminobenzene. Then the intermediates would be degraded to aniline, phenol and benzene sulfonic acid, and eventually decomposed into inorganic substances such as CO₂ and water. ⑤The degradation mechanism of PO₄^3--MEO/Co(Ⅱ) system on MB was the combination of direct electricatalysis on the platinum titanium electrode, with indirect oxidation of the intermediates oxidants like Co³⁺, perphosphoric acid root and hydroxyl radical. The dominant mechanism was the electrocatalysis and its oxidation of Co³⁺.

• Key words：methyl blue dye  PO₄^3--MEO/Co(Ⅱ) electricatalysis reaction system  oxidizing intermediate products  degradation effect of dyes  mechanism of electrocatalysis oxidation

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