Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 106, Taiwan, ROC.
Institute of Food Safety and Health, College of Public Health, National Taiwan University, 17 Xuzhou Rd., Taipei, 100, Taiwan, ROC; Department of Public Health, College of Public Health, National Taiwan University, 17 Xuzhou Rd., Taipei, 100, Taiwan, ROC.
J Hazard Mater. 2021 Jan 15;402:123509. doi: 10.1016/j.jhazmat.2020.123509. Epub 2020 Jul 17.
Polymeric oxygen rich exfoliated graphitic carbon nitride (exfoliated GCN, EGCN) was synthesized by the acid treatment of bulk GCN. The photocatalyst was characterized using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and point of zero charge. EGCN shows high valance band hole transfer under short-time visible light (λ > 420 nm) exposure for photocatalytic mineralization of bisphenol A (BPA). Enhanced BPA removal was achieved by EGCN (99 %) due to formation of OH radicals (HO/h →OH/H). Major factors affecting BPA degradation including catalyst dose, wide pH range, and pollutant concentration were optimized. Repeated cycles of BPA degradation were performed with negligible rate decreased from 0.045 to 0.029 min. The degradation profile and plausible reaction mechanism of BPA was established and well justified by the byproducts identified by mass analysis HR-ESI-MS. Therefore, the as-synthesized metal free EGCN, active under visible light, offers a new platform for complete mineralization of byproducts of halogenated organic contaminants.
通过对块状 GCN 进行酸处理，合成了富氧的层状石墨相氮化碳（层状 GCN，EGCN）。使用 X 射线衍射、扫描电子显微镜、X 射线光电子能谱、傅里叶变换红外光谱和零电荷点对催化剂进行了表征。EGCN 在短时间可见光（λ>420nm）照射下表现出高价带空穴转移，可用于双酚 A（BPA）的光催化矿化。由于形成了 OH 自由基（HO/h→OH/H），EGCN 实现了增强的 BPA 去除（99%）。优化了影响 BPA 降解的主要因素，包括催化剂剂量、宽 pH 范围和污染物浓度。BPA 降解的重复循环进行，速率从 0.045 降至 0.029 min，几乎没有降低。通过质量分析 HR-ESI-MS 鉴定的副产物，建立了 BPA 的降解曲线和合理的反应机制。因此，所合成的无金属 EGCN 在可见光下具有活性，为完全矿化卤代有机污染物的副产物提供了一个新平台。
