2D Conjugated Polymers Containing B←N Units for Improved Photocatalytic Hydrogen Evolution^†

Abstract

Comprehensive SummaryPrevious studies have demonstrated linear polymers embedded with B←N units display efficient photocatalytic hydrogen evolution performance, but their limited structural tunability restricts photogenerated carrier dynamics modulation. Current researches mainly focus on linear polymers, while the study of B←N units in the field of two‐dimension conjugated polymers (2DCPs) photocatalytic hydrogen evolution remains an uncultivated ground. Herein, three 2DCPs containing B←N units were synthesized and their photocatalytic hydrogen production performance was investigated. Among them, the BN‐Tz exhibited the best property with a hydrogen production rate of 89.5 μmol·h–1, while BN‐Ph and BN‐TPB were only 26.4 and 8.5 μmol·h–1, respectively. Comprehensive analyses showed that the remarkable photocatalytic ability of BN‐Tz catalyst was mainly attributed to its superior transport and separation of photogenerated carriers, as well as the ability to construct a stronger built‐in electric field and better planarity. Meanwhile, it was found that the manipulation of the electronic properties of the structures connected to the B←N unit could effectively regulate the molecular polarity, thus achieving the control of the electronic structure of the materials. This work extends the application of materials containing B←N units in photocatalysis and lays a good foundation for the subsequent design of photocatalysts containing B←N units.