Cooperative coupling of hydrogen peroxide (H₂O₂) photosynthesis with organic pollutant degradation is promising strategy applied in chemical synthesis and environmental protection. Nonetheless, the photocatalytic performance is limited by sluggish photogenerated carrier separation and limited redox potentials. Herein, an S-scheme heterojunction was constructed by assembling the TiO₂ nanoparticles and a Schiff-base COF together. The formed S-scheme TiO₂/COF heterojunction can efficiently produce H₂O₂ and degrade Rhodamine B (RhB) synchronously. The S-scheme charge transfer mechanism in TiO₂/COF composite is well unveiled by in situ irradiated X-ray photoelectron spectroscopy and DFT calculation. The femtosecond transient absorption spectra reveal the superior charge migration at interface between TiO₂ and COF. The designed TiO₂/COF composite shows drastically enhanced H₂O₂ yield of 1326 μmol·g^–1·h^–1 in RhB solution, and the AQY value of 4.11% under 420 nm monochromatic light irradiation is achieved. Meanwhile, 100% of RhB degraded under light irradiation for 40 min with TiO₂/TD COF as photocatalyst. This work exemplifies a promising approach to design COF-based S-scheme heterojunction with ameliorative photocatalytic performance for simultaneous organic pollutants degradation and H₂O₂ production.

中文翻译：

---

TiO2/COF S 型异质结中的快速电荷转移促进 H2O2 光合作用和罗丹明 B 降解


过氧化氢 （H₂O₂） 光合作用与有机污染物降解的协同耦合是应用于化学合成和环境保护的有前途的策略。尽管如此，光催化性能受到缓慢的光生载流子分离和有限的氧化还原电位的限制。在此，通过将 TiO₂ 纳米颗粒和席夫基 COF 组装在一起构建了 S 型异质结。形成的 S 型 TiO₂/COF 异质结可以有效地产生 H₂O₂ 并同步降解罗丹明 B （RhB）。通过原位辐照 X 射线光电子能谱和 DFT 计算很好地揭示了 TiO₂/COF 复合材料中的 S 型电荷转移机制。飞秒瞬态吸收光谱揭示了 TiO₂ 和 COF 之间界面处的优越电荷迁移。所设计的 TiO₂/COF 复合材料在 RhB 溶液中 H₂O₂ 产率显著提高，达到 1326 μmol·g^–1·h^–1，在 420 nm 单色光照射下 AQY 值达到 4.11%。同时，在 TiO₂/TD COF 作为光催化剂 40 min 的光照射下，RhB 100% 降解。这项工作展示了一种很有前途的方法，可以设计基于 COF 的 S 型异质结，具有改善光催化性能，可同时降解有机污染物和 H₂O₂ 产生。