Recent advances in metal/covalent organic framework-based materials for photoelectrochemical sensing applications

Owing to its unique features including low background noise, high signal-to-noise ratio, and rapid response, photoelectrochemical (PEC) sensing is a state-of-the-art platform for rapidly and accurately monitoring target compounds. Metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) are key porous crystalline materials that show exceptional potential for application in PEC sensors. A timely and systematic review of the recent progress made and future research trends is valuable for accelerating MOF/COF-based PEC sensor development. This review first discusses the photoactive MOF/COF design principles and key PEC performance control factors by elucidating typical strategies for designing and fabricating photoactive MOFs/COFs to improve photoexcitation, charge separation/transfer. Then, an overview of the considerable progress made in applying MOF/COF-based materials to PEC sensing is presented including pristine MOFs/COFs, MOF/COF-based heterojunctions, MOF derivatives, and MOF/COF hybrids. Finally, the critical challenges for practical applications of MOF/COF-based PEC sensors and the research prospects are briefly discussed.