Low efficiency of photogenerated electron-hole separation has been a challenge for organic conjugated polymer photocatalysts. Our preceding studies have revealed that polymers containing B←N coordination bond can form a localized built-in electric field that effectively promotes photogenerated charge separation. However, B←N coordination units are still scarce and require more examples to find regularities in their structural design. The systematic development and testing of B←N coordination units is necessary for the efficient development of subsequent polymers containing B←N coordination bond. In this work, three conjugated polymers containing B←N coordination bonds, PBN-Ni, PBP-Ni, and PBS-Ni, were synthesized by changing the substituents of the boron atoms and introducing narrow-band thiophene units to form conjugate and energy band gradients. The energy band modulation and localized built-in electric field construction were both achieved as planned, while the bandgap and photogenerated charge transport capabilities caused performance discrepancies. The experimental results showed that PBN-Ni had a better photocatalytic hydrogen evolution (HER) performance, reaching 104.6 µmol h-1 (λ > 420 nm). The optimal optical absorption edge of PBS-Ni was up to 643 nm, but the HER was lower, at 33.2 µmol h-1 (λ > 420 nm, 1 % Pt). PBP-Ni optimized some of the optical absorption efficiencies (511 nm) while ensuring the HER activity (96.6 µmol h-1, λ > 420 nm). This work tentatively explores the characterization of the B←N coordination bond-containing base units serving as photocatalysts and provides the basic model experience and data reference for the subsequent expansion of B←N coordination bond-containing units and the development of B←N coordination bond-containing copolymer systems.

中文翻译：

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通过B←N配位单元的修饰增强光催化产氢


光生电子空穴分离效率低一直是有机共轭聚合物光催化剂面临的挑战。我们前期的研究表明，含有B←N配位键的聚合物可以形成局域内建电场，有效促进光生电荷分离。然而，B←N 协调单元仍然稀缺，需要更多的例子来发现其结构设计的规律性。 B←N配位单元的系统开发和测试对于后续含B←N配位键聚合物的高效开发是必要的。本工作通过改变硼原子的取代基并引入窄带噻吩单元形成共轭和能带，合成了三种含有B←N配位键的共轭聚合物PBN-Ni、PBP-Ni和PBS-Ni梯度。能带调制和局部内置电场构建均按计划实现，但带隙和光生电荷传输能力导致性能差异。实验结果表明，PBN-Ni具有较好的光催化析氢（HER）性能，达到104.6 µmol h-1（λ > 420 nm）。 PBS-Ni 的最佳光学吸收边可达 643 nm，但 HER 较低，为 33.2 µmol h-1（λ > 420 nm，1 % Pt）。 PBP-Ni 优化了一些光学吸收效率 (511 nm)，同时确保 HER 活性 (96.6 µmol h-1, λ > 420 nm)。 该工作初步探讨了含B←N配位键的基本单元作为光催化剂的表征，为后续含B←N配位键单元的拓展和B←N配位的发展提供了基础模型经验和数据参考。含键共聚物体系。