CuNCs-MOFs with hydrogen bonding sites: H2O-induced emission-enhanced phosphorescence-fluorescence conversion and high photo-Fenton catalytic performance

Abstract

Clusters-based metal–organic frameworks (CMOFs) obtained through supramolecular interactions between clusters are expected to be a promising class of materials with interesting properties and attractiveness. Herein, CuNCs protected by AMT (3-amino-1,2,4-triazole-5-thiol) ligands were synthesized, which coordinated with Zn2+ to form a nanosheet CuNCs-MOFs structure, resulting in AIE and enhanced photoluminescence (QY = 1.1 %). Upon aging in H2O, H2O molecules are inserted into S-CuNCs by the hydrogen bond to support 3D microflowers structures, and weak phosphorescence conver to strong fluorescence (28.9 %), simultaneously. After drying, H2O molecules are released by F-CuNCs, which is labled with V-CuNCs, and then easily combined with H2O2, which can be catalyzed to OH by Cu+. Under UV irradiation, CuNCs-MOFs generate photogenerated electrons and holes. As-obtained electrons react with H2O2 to generate more OH, and then catalyze dyes. The remaining holes will also receive electrons given by the dyes. Under the irradiation of Xe lamp, the common three dyes, MB, MO, RB and antibiotic, tetracycline, can be completely degraded within 30 min. Furthermore, under the sunlight, the mixture of dyes and antibiotics also can be completely degraded after 100 min. V-CuNCs show excellent photo-Fenton catalytic performance and have the bright photocatalytic prospects in waste water.