Synthesis of a Novel Pyridine-Containing Vinyl-Linked D-A PM and Its Application in Photocatalytic Hydrogen Peroxide Production

本文以2,4,6-三甲基吡啶为电子供体、2,2′-联吡啶-5,5′-二甲醛为电子受体，通过Knoevenagel缩合反应精准构筑了一种新型乙烯基共价有机聚合物(TBPY-PM)，成功实现了高结晶度有机聚合物(PM)的可控合成，其比表面积高达2029 m²·g−¹，热稳定性测试表明在900℃下仍保留69%质量。光催化性能研究表明，在可见光(λ > 420 nm)驱动下，TBPY-PM通过单电子氧还原路径高效合成H₂O₂，产率可达2023 μmol·g−¹·h−¹，表观量子效率(425 nm处)为18.0%。机理分析表明，其优异性能源于刚性乙烯基连接赋予的宽光谱响应(带隙2.34 eV)、内在的供体受体结构、高载流子迁移率和低电荷转移电阻。在连续16小时循环实验后，实验结果表明材料仍然保持初始活性。本研究为设计高效稳定的PMs光催化剂提供了新策略，在绿色化工与清洁能源领域具有重要应用潜力。In this work, a novel vinyl polymer (TBPY-PM) was precisely constructed by a Knoevenagel reaction using 2,4,6-trimethylpyridine as an electron donor and 2,2′-bipyridine-5,5′-dialdede as an electron acceptor. The controllable synthesis of a high-crystallinity organic polymer (PM) with a specific surface area of up to 2029 m2·g−1 was successfully achieved. Thermal stability tests showed that it retained 69% of its mass at 900˚C. Photocatalytic studies showed that TBPY-PM could efficiently synthesize H₂O₂ through a single-electron oxygen reduction pathway driven by visible light (λ > 420), with a yield of up to 2023 μmol·g−1·h−1 and an apparent quantum efficiency (at 425 nm) 18.0%. Mechanism analysis showed that its excellent performance was due to the wide-spectrum response (band gap 2.34 eV) conferred by rigid vinyl connection, the inherent donor-acceptor structure, high carrier mobility, and low charge transfer resistance. The results showed that the material still maintained its initial activity after 16 hours of continuous cycle experiments. This study provides a new strategy for designing efficient and stable PM photocatalysts, which has important application potential in the fields of green chemical industry clean energy.