Facile synthesis of Ag/AgCl/PAF-54 heterojunction photocatalysts for TC degradation

Abstract

Photocatalysis plays an increasingly important role in the field of water treatment. Among the catalysts, Ag nanoparticles (NPs), a type of noble metal NP, show extraordinary potential for photocatalysis. Nevertheless, the aggregation caused by high surface energy limits their applications. The simple synthesis of Ag NPs with uniform size remains a challenge. In this work, a nitrogen-rich porous organic polymer (POP) with reduction ability, porous aromatic framework (PAF)-54, was chosen as the carrier for the in-situ synthesis of Ag NPs. By virtue of the reducing framework of PAF-54 and the formation of the AgCl/PAF-54 heterojunction, the in-situ reduction of Ag(I) was realized, and thus Ag NPs with the particle size of 20-25 nm were uniformly distributed on PAF-54, which exhibit a strong localized surface plasmon resonance (LSPR) effect. Furthermore, the Ag/AgCl/PAF-54 heterojunction effectively suppresses the recombination of photogenerated electrons and holes, leading to the enhanced photocatalytic ability of the composite material. Even with a small catalyst dosage, rapid tetracycline (TC) degradation can be achieved, and the degradation rate of TC reached 94.8% in 30 min. This study offers a facilitated approach for fabricating Ag-based POP composites with superior photocatalytic properties.