本文要点：
调节光催化剂的电荷行为对于驱动光催化自芬顿反应至关重要。
本文采用微波法成功合成了对称组合为D3h+D3h (TB-TT)和D3h+D2h (TB-CN)的亚乙烯基共价有机骨架，实现了太阳能-H2O2-自芬顿降解的高效转化。
高度对称的TT单元在TB-TT中构建了一个电子供体-受体(D-A)结构，这导致了一个内建电场(IEF)效应，其IEF强度是TB-CN的1.53倍。
这种IEF显著增强激子解离，改善O2吸附和活化，并优化光催化反应途径。在可见光照射下，TB-TT实现了3550 μmol g−1 h−1 的高H2O2产量，并且将H2O2有效转化为羟基自由基(⋅OH)。
此外，光催化自芬顿反应通过羟基化将磺胺甲恶唑(SMX)降解为小分子产物，降解率达到98 %。这项工作揭示了对称单元增强光催化剂IEF效应的机理及其在高级氧化反应中的潜力。
Scheme 1. Synthesis and structure of TB-TT and TB-CN.
Fig. 1. PXRD of (a) TB-TT and (b) TB-CN. (c) XPS C 1s spectra of TB-TT and TB-CN. Solid-state 13C NMR spectra of (d) TB-TT and (e) TB-CN. (f) FT-IR of TB-TT and TB-CN
Fig. 2. (a) TEM images, (b, c) EDX elemental mapping of TB-TT and TB-CN. (d) TG-DTG curves of TB-TT. (e) UV-vis DRS spectra with Tauc plots as insets, (f) band structure diagrams, (g) transient photocurrent responses, (h) EIS spectra, and (i) PL spectra of TB-TT and TB-CN
Fig. 3. (a) TRPL spectra. (b) H2O2 yield of TB-TT and TB-CN. (c) AQY of TB-TT. (d) Photocatalytic cycling tests of two COFs. (e) H2O2 production rates under different sacrificial agents.. (f) EPR spectra of ‧O2 -. (g) In situ DRIFT spectrum and (h) HOMO and LUMO distribution diagrams of TB-TT.
Fig. 4. Electron-hole distributions of (a) TB-TT and (b) TB-CN after photoexcitation. Work function spectra of (c) TB-TT and (d) TB-CN. (e) The O2 adsorption site and configuration on TB-TT. (f) Charge density isosurface map. (g) Free-energy diagrams for the reduction of O2 to H2O2 on the TB-TT.
Fig. 5. (a) Degradation efficiency of SMX by TB-TT and TB-CN in pure water and the corresponding rate constants (inset). (b) Rate constants for the quenching experiments of SMX degradation in the TB-TT system. (c) The SMX degradation rate of TB-TT in real water systems. (d) UPLC results of SMX degradation by TB-TT in rainwater. (e) SMX removal efficiency and rate constants (inset) by TB-TT in rainwater containing coexisting anions. (f) Photocatalytic selfFenton degradation rates of SMX by TB-TT under different Fe2+ concentrations.
Fig. 6. TB-TT and TB-CN photocatalytic H2O2 production and self-Fenton-degraded SMX mechanism diagrams.
https://doi.org/10.1016/j.apcatb.2025.125062
