分别以聚丙烯晴(PAN)基石墨毡(GF)和粘胶基石墨毡为固体催化电极,通过不同阴极电位下电化学生成H₂O₂的浓度表征2种电极氧还原反应(ORR)的活性,考察了在最佳电位下,2种电极对亚甲基蓝(MB)的降解效果。利用扫描电镜(SEM)、视频光学接触角测量仪、X射线衍射仪(XRD)和拉曼光谱表征2种石墨毡的表面结构和石墨化程度,利用电化学阻抗测试(EIS)、线性扫描伏安法(LSV)和循环伏安法(CV)分析2种石墨毡的电化学性质。结果表明,石墨化程度较大的粘胶基石墨毡表面惰性强,降低了氧活性物质的积聚,阻碍了ORR的进行。而PAN基石墨毡具有更大的电活性面积,从而有利于ORR的发生。在溶液pH为3、Fe²⁺浓度为0.3 mmol/L、外加电位为-0.85 V、氧气流量为300 mL/min条件下,90 min时PAN基石墨毡的H₂O₂产量可达160.7 mg/L,对100 mg/L亚甲基蓝的矿化率为58%。

Polyacrylonitrile (PAN)-based graphite felt (GF) and viscose-based graphite felt are respectively used as solid catalytic electrodes,their activities in oxygen reduction reaction (ORR) are characterized through electrochemical generation of H₂O₂ concentration at different cathode potentials.The degradation efficiencies of methylene blue (MB) by these two electrodes are investigated at the optimum potential.The surface structure and graphitization degree of two kinds of graphite felt are characterized by means of scanning electron microscopy (SEM),optical contact angle measuring instrument,X-ray diffractometer and Raman spectroscopy.The electrochemical properties of graphite felts are analyzed by means of electrochemical impedance measurement (EIS),linear sweep voltammetry (LSV) and cyclic voltammetry (CV).It is shown that viscose-based graphite felt with high graphitization degree has a strong surface inertia,which reduces the accumulation of oxygen active substances and hinders the progress of ORR.In contrast,PAN-based graphite felt has a larger electroactive area,which is conducive to ORR.The production of H₂O₂ over PAN-based graphite felt can reach 160.7 mg·L^-1 and the mineralization rate of 100 mg·L^-1 methylene blue by PAN-based graphite felt reaches 58% when pH=3,the concentration of Fe²⁺ is 0.3 mmol·L^-1,the applied potential is -0.85 V,the flow rate of oxygen is 300 mL·min^-1,and the reaction lasts for 90 min.

郭泓凯(1998-),男,硕士研究生,研究方向为电催化污水处理,guokaiqi520@126.com