摘要：

以多孔六方氮化硼（p-BN）和PbO₂共掺杂制备具有疏水外层的p-BN@β-PbO₂电极，并用于电化学氧化降解盐酸强力霉素（DC）。利用SEM、EDS、XRD表征了电极的形貌及组成，通过LSV、CV和EIS测定了电极的电化学性能，并探讨了电压、DC初始浓度、pH、电解质类型及浓度等因素对DC降解效果的影响，分析了DC的降解机理。结果表明，具有疏水外层修饰的p-BN@β-PbO₂电极具有较高的析氧电位，更不容易发生副反应，对污染物的降解属于间接氧化，且10% p-BN@β-PbO₂电极的电化学活性面积和电催化活性最高。p-BN@β-PbO₂电极降解DC的最佳条件为有疏水外层、10% p-BN掺杂量、DC初始质量浓度30 mg/L、pH=4.69、电压10 V、电解质NaCl浓度0.05 mol/L等，120 min时DC降解率最高可达96.29%。经8次循环使用，10% p-BN@β-PbO₂电极仍能保持超过83.60%的DC降解率，且Pb元素溶出量较低。HPLC-MS技术证实该电极系统产生的活性物质（如·OH和活性氯物种）能高效攻击DC分子中的—NH₂支链和苯环上的C \stackrel{}{̿}C双键，导致共轭结构被破坏和逐步分解，最终实现DC的快速降解。

关键词: 电催化, 盐酸强力霉素, 多孔六方氮化硼, β-PbO₂电极

Abstract:

A p-BN@β-PbO₂ electrode with a hydrophobic outer layer was prepared by co-doping porous hexagonal boron nitride(p-BN) and PbO₂, and used for electrochemical oxidation degradation of doxycycline hydrochloride(DC). The morphology and composition of the electrode were characterized by SEM, EDS, and XRD. The electrochemical performance of the electrode was determined by LSV, CV, and EIS. The effects of voltage, initial DC concentration, pH, electrolyte type and concentration on DC degradation were analyzed, and DC degradation mechanism was studied. The results showed that p-BN@β-PbO₂ electrode with hydrophobic outer layer modification had a higher oxygen evolution potential and was less prone to side reactions. The degradation of pollutants belonged to indirect oxidation. The 10% p-BN@β-PbO₂ electrode had the highest electrochemical active area and electrocatalytic activity. The optimal conditions for DC degradation by p-BN@β-PbO₂ electrode were the presence of a hydrophobic outer layer, 10% p-BN doping, initial DC concentration of 30 mg/L, pH=4.69, voltage of 10 V and electrolyte NaCl concentration of 0.05 mol/L. The highest DC degradation rate could reach 96.29% after 120 minutes. After 8 cycles of use, 10% p-BN@β-PbO₂ electrode still maintained DC degradation rate of over 83.60%, and the leaching amount of Pb element was relatively low. HPLC-MS technology confirmed that the active substances generated by the electrode system, such as ·OH and active chlorine species, could efficiently attack —NH₂ branch in DC molecules and C \stackrel{}{̿}C double bond on the benzene ring, causing the conjugated structure to be destroyed and gradually decomposed, ultimately achieving rapid degradation of DC.

Key words: electrocatalysis, doxycycline hydrochloride, porous hexagonal boron nitride, β-PbO₂ electrode

中图分类号: 

• X703.1