Integrating MXene into β‑ketoenamine-based covalent organic frameworks for boosting photocatalytic hydrogen production

Covalent organic frameworks (COFs) are emerging porous crystal materials with adjustable composition, structure and function, which provides a tunable platform for photocatalysis. There are still challenges in improving the photochemical properties of COFs. Therefore, we choose to design and prepare β-ketoenamine-linked COFs with high stability and covalently connect them with MXene based on Schiff base reaction. The ordered structure, visible light absorption and band gap of MXene/COF composites are optimized by different ratios of composites. The results show that MXene 0.5 /TAPB-Tp-COF has the best performance, with a specific surface area of 460.88 m 2 /g and a hydrogen production rate of 3360 μmol·g −1 ·h −1 , which is 26.67 times that of pure TAPB-Tp-COF. The MXene/TAPB-Tp-COF heterostructure engineering effectively retains the inherent microporous architecture and high surface area of pristine COFs, while introducing interfacial charge transfer channels that boost photogenerated carrier separation efficiency and accelerate charge migration kinetics. This covalent composite method has promoted the research and development of COFs-based photocatalysts. This covalent composite method is beneficial to the research and development of COFs-based photocatalysts.