Three-Component Donor−π–Acceptor Covalent–Organic Frameworks for Boosting Photocatalytic Hydrogen Evolution
Ziping Li, Tianqi Deng, Si Ma, Zhenwei Zhang, Gang Wu, Jiaao Wang, Qizhen Li, Hong Xia, Shuo‐Wang Yang, Xiaoming Liu
Abstract
Two-dimensional covalent–organic frameworks (2D COFs) have recently emerged as great prospects for their applications as new photocatalytic platforms in solar-to-hydrogen conversion; nevertheless, their inefficient solar energy capture and fast charge recombination hinder the improvement of photocatalytic hydrogen production performance. Herein, two photoactive three-component donor−π–acceptor (TCDA) materials were constructed using a multicomponent synthesis strategy by introducing electron-deficient triazine and electron-rich benzotrithiophene moieties into frameworks through sp 2 carbon and imine linkages, respectively. Compared with two-component COFs, the novel TCDA-COFs are more convenient in regulating the inherent photophysical properties, thereby realizing outstanding photocatalytic activity for hydrogen evolution from water. Remarkably, the first sp 2 carbon-linked TCDA-COF displays an impressive hydrogen evolution rate of 70.8 ± 1.9 mmol g –1 h –1 with excellent reusability in the presence of 1 wt % Pt under visible-light illumination (420–780 nm). Utilizing the combination of diversified spectroscopy and theoretical prediction, we show that the full π-conjugated linkage not only effectively broadens the visible-light harvesting of COFs but also enhances charge transfer and separation efficiency.