College of Science, Huazhong Agricultural University, Shizishan Avenue, Wuhan, 430070, P. R. China.
College of Chemistry, Central China Normal University, Luoyu Road No. 152, Wuhan, 430079, P. R. China.
Chemistry. 2019 Mar 1;25(13):3362-3368. doi: 10.1002/chem.201805740. Epub 2019 Feb 6.
Donor-acceptor (D-A) conjugated polymers have proved to be desired candidates to couple with inorganic semiconductors for enhanced photocatalytic activity. Herein, the matched energy levels between polymer BFB and TiO make them form BFB-TiO composites with moderate photocatalytic H evolution rate (HER). To further enhance the interfacial interaction, BFB was modified with a carboxylic acid end group, which reacted with surface OH of TiO to form an ester bond. As a result, the functionalized BFBA-TiO composites exhibited superior photocatalytic activity. Especially, HER of 4 % BFBA-TiO can reach up to 228.2 μmol h under visible light irradiation (λ>420 nm), which is about 2.02 times higher than that of BFB-TiO . The enhanced photocatalytic activity originated from the formed ester bond between polymer and TiO , and photogenerated electrons injection from lowest unoccupied molecular orbital (LUMO) of the exited polymer to conduction band of TiO were accelerated. Therefore, based on an intermolecular interaction mechanism, more suitable D-A conjugated polymers with anchoring groups could be designed to couple with other semiconductors for enhancing photocatalytic activity.
供体-受体（D-A）共轭聚合物已被证明是与无机半导体结合以提高光催化活性的理想候选材料。本文中，聚合物 BFB 与 TiO 的能级匹配使它们形成 BFB-TiO 复合材料，具有适度的光催化析氢速率（HER）。为了进一步增强界面相互作用，BFB 被修饰上了一个羧酸端基，它与 TiO 的表面 OH 反应形成酯键。结果，功能化的 BFBA-TiO 复合材料表现出优异的光催化活性。特别是，在可见光照射下（λ>420nm），4% BFBA-TiO 的 HER 可以达到 228.2 μmol·h-1，约为 BFB-TiO 的 2.02 倍。增强的光催化活性源于聚合物和 TiO 之间形成的酯键，以及从激发态聚合物的最低未占据分子轨道（LUMO）到 TiO 导带的光生电子注入加速。因此，基于分子间相互作用机制，可以设计具有锚固基团的更合适的 D-A 共轭聚合物与其他半导体结合，以提高光催化活性。
