Copper mixed-triazolate frameworks featuring the thiophene-containing ligand towards enhanced photodegradation of organic contaminants in water.

By using a thiophene-containing triazole ligand -3,5-di(thiophen-2-yl)-1H-1,2,4-triazole (3,5-Th-tzH) and 3,5-diphenyl-1H-1,2,4-triazole (3,5-Ph-tzH) in different molar ratio in the reactant, copper(I) mixed-triazolate frameworks CuMtz-1 {[Cu(3,5-Ph-tz)(3,5-Th-tz)](BF)(CHOH)} (x = 0.5 for CuMtz-1a and 1.1 for CuMtz-1b) were firstly synthesized and characterized by PXRD, IR, H NMR, SEM, TG and UV-vis DRS. They have been evaluated as photocatalysts for the degradation of organic pollutants in water. It was found that the rate constants towards the degradation of both traditional and emerging organic contaminants over CuMtz-1b were significantly improved, i.e. by 160% for methyl orange, 210% for rhodamine B, 80% for methyl blue and 180% for sulfasalazine in comparison with that catalyzed over the parent MOF CuTz-1 {[Cu(3,5-Ph-tz)](BF)(CHOH)} under Xe lamp irradiation in the absence of HO. More importantly, the degradation efficiency of methyl orange and sulfasalazine by CuMtz-1b without the addition of HO was quite comparable with that by CuTz-1 with the addition of HO under both Xe lamp irradiation and natural sunlight. The enhancement on the degradation efficiency can be attributed to the increased light absorption ability and the change of the band structure caused by the incorporation of thiophene-containing triazole ligand.