Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, PR China.
Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, PR China.
Environ Res. 2022 Sep;212(Pt D):113508. doi: 10.1016/j.envres.2022.113508. Epub 2022 May 22.
Heteroatom-doped carbon materials can effectively activate HO into •OH during the metal-free electro-Fenton (EF) process. However, information on bifunctional catalysts for the simultaneous generation and activation of HO is scarce. In this study, O- and F-doped porous carbon cathode materials (PPCs) were prepared by the direct carbonization of polyvinylidene fluoride (PVDF) for sulfamerazine (SMR) removal in a metal-free EF process. The porous structure and chemical composition of the PPCs were regulated by the carbonization temperature. PPC-6 (carbonized at 600 °C) exhibited optimal electrocatalytic performance in terms of electrochemical HO generation and activation owing to its high specific surface area, mesoporous structure, and optimum fractions of doped O and F. Excellent performance of the 2e oxygen reduction reaction was found with an HO selectivity of 93.5% and an average electron transfer number of 2.13. An HO accumulative concentration of 103.9 mg/L and an SMR removal efficiency of 90.1% were achieved during the metal-free EF process. PPC-6 was able to stably remove SMR over five consecutive cycles, retaining 92.6% of its original performance. Quantitative structure-activity relationship analysis revealed that doped oxygen functional groups contributed substantially to HO generation, and semi-ionic C-F bonds with high electronegativity were the cause of the activation of HO to •OH. These findings suggest that the PVDF-derived carbonaceous catalysts are feasible and desirable for metal-free EF processes.
杂原子掺杂碳材料可以在无金属电芬顿（EF）过程中有效地将 HO 激活为•OH。然而，关于同时生成和激活 HO 的双功能催化剂的信息却很少。本研究通过聚偏二氟乙烯（PVDF）的直接碳化制备了 O 和 F 掺杂的多孔碳阴极材料（PPCs），用于在无金属 EF 过程中去除磺胺甲恶唑（SMR）。PPCs 的多孔结构和化学成分通过碳化温度进行调节。PPC-6（在 600°C 碳化）由于具有高比表面积、中孔结构和最佳掺杂 O 和 F 分数，在电化学 HO 生成和激活方面表现出最佳的电催化性能。发现 2e 氧还原反应具有出色的性能，HO 选择性为 93.5%，平均电子转移数为 2.13。在无金属 EF 过程中，HO 累积浓度达到 103.9mg/L，SMR 去除效率达到 90.1%。PPC-6 能够在五个连续循环中稳定地去除 SMR，保留其原始性能的 92.6%。定量结构-活性关系分析表明，掺杂的氧官能团对 HO 的生成有很大贡献，而具有高电负性的半离子 C-F 键是 HO 激活为•OH 的原因。这些发现表明，源自 PVDF 的碳质催化剂在无金属 EF 过程中是可行且理想的。
