Abstract A novel anode based on PbO2-GNRs nanocomposites was synthesized in order to investigate the simultaneous electrochemical oxidation of phenolic compounds in a mixture of methyl and chloro substituted phenols in alkaline solution (pH = 8.3). The crystal structure, morphology and composition of the synthesized materials were characterized using X-ray powder diffraction (XRPD), field emission scanning electron microscopy with energy dispersive X-ray spectrometer (FESEM-EDX) and transmission electron microscopy (TEM). FESEM images confirmed the presence of PbO2 nanoparticles on the PbO2-GNRs composite. The cyclic voltammetry measurements of the PbO2-GNRs electrode in 0.1 M Na2SO4 electrolyte indicated the electrochemical oxidation of phenol via indirect mechanism by hydroxyl radicals. Electrolytic oxidation of phenolic compounds was performed under potentiostatic conditions at potentials 2.3 V and 3 V. Removal efficiency of phenolic compounds increased with increasing the time of electrolysis and applied potential, up to 78% for 300 min and potential of 3 V. GC–MS chromatograms confirmed that mechanism of phenolic compounds degradation is based on their dechlorination and demethylation followed by the process of aromatic ring degradation. Newly synthesized PbO2-GNRs as electrode material could be successfully implemented in wastewater treatment of phenolic compounds by the electrochemical oxidation process.

中文翻译：

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使用 PbO2-GNRs 阳极电化学氧化基础介质中酚类化合物的复杂混合物

摘要 为了研究在碱性溶液（pH = 8.3）中甲基和氯代苯酚混合物中酚类化合物的同时电化学氧化，合成了一种基于 PbO2-GNRs 纳米复合材料的新型阳极。使用X射线粉末衍射（XRPD）、场发射扫描电子显微镜（FESEM-EDX）和透射电子显微镜（TEM）表征合成材料的晶体结构、形貌和组成。FESEM 图像证实了 PbO2-GNRs 复合材料上存在 PbO2 纳米颗粒。PbO2-GNRs 电极在 0.1 M Na2SO4 电解质中的循环伏安测量表明苯酚通过羟基自由基的间接机制进行电化学氧化。酚类化合物的电解氧化在电位为 2.3 V 和 3 V 的恒电位条件下进行。酚类化合物的去除效率随着电解时间和施加电位的增加而增加，在 300 分钟和 3 V 电位下可达 78%。GC-MS色谱图证实酚类化合物的降解机制是基于它们的脱氯和去甲基化，然后是芳香环的降解过程。新合成的 PbO2-GNRs 作为电极材料可以通过电化学氧化过程成功地用于酚类化合物的废水处理。GC-MS 色谱图证实酚类化合物的降解机制是基于它们的脱氯和去甲基化，然后是芳环降解过程。新合成的 PbO2-GNRs 作为电极材料可以通过电化学氧化过程成功地用于酚类化合物的废水处理。GC-MS 色谱图证实酚类化合物的降解机制是基于它们的脱氯和去甲基化，然后是芳环降解过程。新合成的 PbO2-GNRs 作为电极材料可以通过电化学氧化过程成功地用于酚类化合物的废水处理。