Construction of zirconium metal–organic polyhedron/silver chloride heterojunction with boosted photocatalytic activity for the degradation of broad-spectrum antibiotics and mechanism insight

Abstract

Zr-based metal–organic polyhedra (Zr-MOPs) have focused the spotlight on photocatalytic applications, mainly owing to their excellent properties in tunable semiconducting characteristics and outstanding water stability. Herein, AgCl nanoparticles were incorporated into an amino-functionalized zirconium metal–organic tetrahedron (denoted as ZrT-1-NH2) by a facile in-situ growth method, leading to the formation of AgCl/ZrT-1-NH2 composites. Photocatalytic activity under visible light was assessed via degrading broad-spectrum antibiotics (including tetracyclines and quinolones). The effect of important parameters, including pH value, catalyst dosage, initial antibiotic concentration and the weight ratio of AgCl to ZrT-1-NH2, were investigated. As a consequence, the 30 wt% AgCl/ZrT-1-NH2 composites shows enhanced ability in photolysis of chlortetracycline, oxytetracycline, norfloxacin and tetracycline (irradiated for 90 min at λ > 420 nm), and the degradation efficiencies were 79.45 %, 72.65 % and 73.27 % and 83.99 %, respectively. Based on the characterization results, Z-scheme heterojunction and surface plasmon resonance (SPR) effect (caused by a small quantity of Ag nanoparticles) significantly promote the separation of photoelectron and hole. This research will introduce new ideas for the synthesis of Zr-MOP based composites, and exhibit a promising strategy to establish MOP-based heterojunction for environmental remediation.