Abstract:

A series of N and S doped and modified biocarbon fiber materials NSC-X were synthesized by high-temperature pyrolysis. The samples were characterized by various techniques. Sulfisoxazole (SSX) was selected as for degradation in water, and the degradation effect and mechanism of SSX by NSC-X activated peroxysulfate (PMS) were studied. The experimental results showed that the doping of N and S elements significantly improved the degradation performance of the activated PMS. The catalytic performance of NSC-5 was the best. When the dosage of NSC-5 was 0.4g/L and the PMS and SSX concentrations were 0.25mmol/L and 10mg/L, more than 80% of SSX was removed after 90 minutes of reaction, and the reaction rate was 2.7 times of that with biological carbonaceous material (BC) involved in the reaction. Electron paramagnetic resonance (EPR) showed that the main active species in the degradation included singlet oxygen (¹O₂), sulfate radical (·SO{}_{\mathrm{4}}^{-}) and hydroxyl radical (·OH). The doping of nitrogen and sulfur accelerated the electron transfer rate, thereby increasing the catalytic activity of the materials.

Key words: biomass, heteroatom, catalyst, activation, peroxymonosulfate (PMS), sulfisoxazole (SSX), radical

摘要：

利用高温热解的方式制备由氮、硫元素掺杂改性的生物碳质纤维材料，并借用扫描电镜（SEM）、X射线衍射（XRD）、X射线光电子能谱（XPS）等多种技术对材料性质进行分析。实验以制备材料为催化剂活化过一硫酸盐（PMS）降解水中的磺胺异唑（SSX），研究其降解效果，探讨材料活化PMS的机理。结果表明：N、S的掺杂显著提升了材料活化PMS降解SSX的性能，其中NSC-5的催化性能最佳，当NSC-5投加量为0.4g/L、PMS浓度为0.25mmol/L、SSX浓度为10mg/L时，反应90min后可去除80%以上，反应速率是生物碳质材料（BC）参与进行反应的2.7倍，这与其表面增加的官能团相关。电子顺磁共振（EPR）结果表明，SSX降解过程中起主要作用的组分是单线态氧（¹O₂）、硫酸根自由基（·SO{}_{\mathrm{4}}^{-}）和羟基自由基（·OH），氮硫的掺杂加快了电子转移速率，进而提高材料的催化活性。

关键词: 生物质, 杂原子, 催化剂, 活化, 过一硫酸盐, 磺胺异唑, 自由基