Constructing two-dimensional heterojunction through decorating covalent organic framework with MoS2 for enhanced photoelectrochemical water oxidation

Abstract Photoelectrochemical (PEC) water splitting is regarded as one of the most effective route to address energy crisis and environmental issues. Two-dimensional covalent organic frameworks (2D COFs) have made some advances in PEC water splitting owing to their functionalized building blocks, remarkable structural stability, and unique conjugated structures, etc. Unfortunately, the PEC performance of COFs is severely hindered because of the poor surface charge transfer, surface recombination at the photoanode/electrolyte junction, and sluggish oxygen evolution reaction (OER) kinetics. Herein, we report an efficient 2D heterojunction through decorating a 2D COF with MoS2 for enhanced PEC water oxidation. The photocurrent density and incident photon conversion efficiency (IPCE) of the resultant photoanode are effectively improved by constructing 2D COF-based heterojunction. Such a strategy of constructing 2D heterojunction can not only efficiently accelerate the charge separation and transfer but also promote the separation of photogenerated electron-hole pairs for oxygen evolution. This work provides rational suggestions for developing COF-based photocatalysts to address the energy crisis and various environmental issues.