Enhanced Built‐in Electric Field Promotes Photocatalytic Hydrogen Performance of Polymers Derived from the Introduction of B←N Coordination Bond

High concentrations of active carriers on the surface of a semiconductor through energy/electron transfer are the core process in the photocatalytic hydrogen production from water. However, it remains a challenge to significantly improve photocatalytic performance by modifying simple molecular modulation. Herein, a new strategy is proposed to enhance the photocatalytic hydrogen evolution performance using boron and nitrogen elements to construct B←N coordination bonds. Experimental results show that polynaphthopyridine borane (PNBN) possessing B←N coordination bonds shows a hydrogen evolution rate of 217.4 µmol h(−1), which is significantly higher than that of the comparison materials 0 µmol h(−1) for polyphenylnaphthalene (PNCC) and 0.66 µmol h(−1) for polypyridylnaphthalene (PNNC), mainly attributed to the formation of a strong built‐in electric field that promotes the separation of photo‐generated electrons/holes. This work opens up new prospects for the design of highly efficient polymeric photocatalysts at the molecular level.