Bi2WO6/TiO2异质结光催化臭氧氧化头孢曲松钠性能及机理研究
- Performance and mechanism of photocatalytic ozonation of ceftriaxone sodium by Bi2WO6/TiO2 heterojunction under simulated solar light
- 基金项目：生物膜法水质净化及利用技术教育部工程研究中心开放基金 (No. BWPU2023KF05)
- 摘要：本研究采用水热法合成了Bi2WO6/TiO2 (BT)异质结催化剂，利用XRD、SEM、TEM、XPS、UV-Vis DRS、IT和EIS等方法对催化剂的形貌结构、组成和光电性能进行表征，并考察其模拟太阳光下催化臭氧氧化头孢曲松钠 (CRO)的性能. 结果表明，TiO2成功掺杂于Bi2WO6表面，形成的BT异质结提高了光生电荷-空穴的分离效率，提升了CRO的去除率. 光照180 min后，溶液中CRO和TOC去除率分别为88.6%和81.3%，光催化和臭氧氧化的协同作用系数为1.4. 五次循环使用后CRO降解率仍为79.2%，表明BT有较好的催化活性和稳定性.根据自由基捕获实验和ESR测试结果，提出了BT Z-型异质结的电子传递路径和CRO的光催化臭氧氧化机理. 通过对 CRO降解中间体的分析，提出了可能的降解途径.
- Abstract：The Bi2WO6/TiO2 (BT) heterojunction catalyst was prepared by hydrothermal method. The morphology, composition and photoelectric performance of the as-prepared catalyst were characterized by XRD, SEM, TEM, XPS, UV-Vis DRS, IT and EIS. The photocatalytic ozonation performance of BT toward ceftriaxone sodium (CRO) under simulated solar light (SSL) was also investigated. The results showed that TiO2 was successfully doped on the surface of Bi2WO6, the formation of heterojunction improved the efficiency of photo-generated e--h+ separation and enhanced the degradation of CRO. The removal efficiency of CRO and TOC reached to be 88.6% and 81.3% after 180 min of simulated solar light irradiation. The synergy index was 1.4 for SSL/BT/O3 system. The degradation efficiency of CRO remained above 79.2% after 5 consecutive cycles, demonstrating the excellent catalytic activity and high stability of BT. We put forward a new Z-scheme transfer pathway of electrons and the degradation mechanism based on the results of radical trapping experiments and electron spin resonance measurements. In addition, we proposed the possible degradation pathways of CRO through analysis of the degradation intermediates.
