TiO2-NB/pg-C3N4可见光催化降解17α-乙炔雌二醇的机理

通过煅烧自制的TiO₂纳米带（TiO₂-NB）和多孔氮化碳（pg-C₃N₄）制备出新型的TiO₂纳米带/多孔氮化碳（TiO₂-NB/pg-C₃N₄）光催化剂，优化了其制备条件，并用于可见光条件下催化降解雌激素活性最强的17α-乙炔雌二醇（EE2）.通过SEM、TEM、XRD、UV-vis DRS、PL、XPS和BET等手段对催化剂结构和表面物理化学性质进行表征和分析.结果表明，B型TiO₂纳米带均匀负载至多孔氮化碳薄片上，形成TiO₂-NB/pg-C₃N₄复合光催化剂.最优条件下制备的TiO₂-NB/pg-C₃N₄降解EE2的速率常数（0.02537min^-1）分别是TiO₂-NB （0.00197min^-1）和pg-C₃N₄（0.0077min^-1）的12.88倍和3.29倍.自由基捕获实验结果显示超氧自由基（·O₂^-）是TiO₂-NB/pg-C₃N₄可见光催化降解EE2的主要活性物种.HPLC-MS中间体检测结果显示，可能的降解中间体主要有4个，提出可能的降解途径，而且通过MCF-7雌激素活性测试法可知降解过程产物的雌激素活性基本消除.

The degradation mechanism study of 17α-ethinylestradiol by TiO2 nanobelt/pg-C3N4 photocatalyst under visible light irradiation

TiO₂-NB/pg-C₃N₄ photocatalysts were prepared using prepared porous C₃N₄ nanosheets and TiO₂ nanobelts via grinding and followed calcination, and the preparation conditions were optimized. The prepared materials were used to remove 17α-ethynylestradiol(EE2) under visible light irradiation, which has most potent estrogenic activity. The structure and surface physical-chemical properties of them were comprehensively investigated by scanning electron microscope (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), ultraviolet visible diffuse reflectance spectroscopy (UV-Vis DRS), photoluminescence spectroscopy (PL), X-ray photoelectron spectroscopy (XPS) and N₂ adsorption-desorption isotherms (BET). The results showed that the B-type TiO₂ nanobelts were anchored onto porous C₃N₄ nanosheets to form TiO₂-NB/pg-C₃N₄ composite photocatalyst. The degradation rate constants of EE2 on TiO₂-NB/pg-C₃N₄ (0.02537min^-1) was 12.88 times and 3.29 times than those on pure TiO₂-NB(0.00197min^-1) and pg-C₃N₄(0.0077min^-1). Active species capture experiments showed that ·O₂^- was the main active specie in the EE2 degradation process on TiO₂-NB/pg-C₃N₄. The HPLC-high resolution mass spectrum (HPLC-HRMS) measurement results showed that there were 4 intermediates and possible degradation route was proposed. Moreover, the estrogenic activity measurement by MCF-7method during degradation process showed that TiO₂-NB/pg-C₃N₄ can effectively eliminate the estrogenic activity without producing by-products with more estrogenic activity.