The facile boosting sunlight-driven photocatalytic performance of a metal–organic-framework through coupling with Ag2S nanoparticles

Abstract

Metal–organic frameworks (MOFs) are novel types of porous crystal materials that display unique structures and features, such as versatile and modular frameworks, ligand-to-metal charge transfer transitions, and have unusual adsorptive capabilities for target molecules. MOF materials have demonstrated potential for numerous applications in recent years, particularly photocatalysis. Nevertheless, their photocatalytic performances are still unsatisfactory due to their rapid recombination of charge carriers. In this study, a facile method was successfully developed to tremendously boost the sunlight-driven photocatalytic performance of a MOF material (MIL-53(Fe)) by coupling with silver sulfide (Ag₂S) nanoparticles for the first time. The prepared catalysts were characterized in detail. Their photocatalytic and photo-Fenton catalytic performances were assessed via the degradation of tetracycline (TC) and rhodamine B (RhB). The results indicate that the fabricated Ag₂S/MIL-53(Fe) heterojunction composites exhibit much enhanced photocatalytic activities as compared with bare MIL-53(Fe) and Ag₂S. The greatly enhanced catalytic activity can be ascribed to the formation of a heterojunction with intimate interface contact, which promotes the transfer and separation of charge carriers, decreases band gap, increases light absorption, and increases the specific surface area. Moreover, the addition of H₂O₂ can further enhance the degradation efficiency due to the synergistic effects of the photo and Fenton catalysis. This work provides new insight into the development of a facile method to highly improve the photocatalytic performance of MOF materials for environmental remediation.