碳纳米管掺杂PbO_(2)复合电极的制备及其催化氧化双酚A

FABRICATION OF CARBON NANOTUBE-DOPED PbO_(2) COMPOSITE ELECTRODE AND MECHANISM OF CATALYTIC OXIDATION OF BISPHENOL A

采用电化学沉积法将不同浓度的碳纳米管(CNT)掺入PbO_(2)电极,得到具有高稳定性和催化活性的CNT-PbO_(2)复合电极。扫描电子显微镜(SEM)、能量色散谱(EDS)等测试分析发现CNT掺杂到PbO_(2)电极表面活性层中,CNT掺杂使得PbO_(2)晶粒尺寸减小,活性表面积增大。CNT-PbO_(2)电极降解双酚A体系中自由基生成量减少,但其降解效果反而提升。循环伏安测试(CV)、电极加速寿命测试表明,CNT-PbO_(2)电极降解双酚A的机理主要是改性后的电极具有更强的电化学直接氧化能力和更高的稳定性。最后通过UPLC&Q-TOF MS测试得到双酚A的主要降解产物和降解路径。

CNT-PbO_(2) composite electrodes with high stability and catalytic activity were obtained by doping carbon nanotubes(CNTs) with different concentrations into PbO_(2) electrodes by electrochemical deposition. Scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) analysis proved that CNTs were successfully doped into the PbO_(2) electrode surface active layer, leading to a decline of PbO_(2) particle size and an increase of activity surface area. The amount of ·OH radicals generated in the degradation system of bisphenol A(BPA) by CNT-PbO_(2) electrodes decreased. However, the degradation effect was improved. Cyclic voltammetry(CV) curves and the accelerated life test indicated that the degradation mechanism of BPA was mainly ascribed to the stronger electrochemical direct oxidation ability and higher stability of CNT-PbO_(2) composite electrodes. Finally, the dominant by-products were obtained, and plausible degradation pathway of BPA was proposed by UPLC & Q-TOF MS test.