Coupling plasmonic effect into stable AgCl/NH2-MIL-68In Z-scheme heterojunction system for efficient photodegradation of levofloxacin

Unstable contact interface, inferior charge transmission efficiency and low redox capability significantly inhibit the photocatalytic property of heterojunctions. Herein, a stable AgCl/NH2-MIL-68In Z-scheme heterojunction that couples with plasmonic Ag nanoparticles (NPs) to promote efficient long-range charge separation is rationally designed. This heterostructure is successfully fabricated by the in-situ growth of AgCl and Ag NPs on the surface and framework of NH2-MIL-68In via a facile ion exchange precipitation approach. Benefiting from the surface plasmon resonance (SPR) effect of Ag NPs and the interfacial heterojunction, the visible light response is enhanced and the recombination rate of photogenerated charges is weakened. Impressively, the artificial Zscheme heterojunction exhibits superior photocatalytic activity for levofloxacin degradation. Furthermore, the adjustment of the AgCl and Ag NPs loading ratio of NH2-MIL-68In further improves the photocatalytic degradation activity of levofloxacin (0.0222 min-1), which is much higher than that of pure NH2-MIL-68In (k = 0.00121 min-1) and AgCl (k = 0.00093 min-1). This work not only develops an effective photocatalyst for the degradation of organic pollutants, but also provides a promising sight for feasible designing the more stable Zscheme heterojunction with efficient charge separation efficiency.