A new 3D 8-connected Cd(ii) MOF as a potent photocatalyst for oxytetracycline antibiotic degradation

Abstract

The incremental use of antibiotics is now posing a pollution problem in the aquatic system. Therefore, it is necessary to decompose this class of harmful components existing in wastewater. Metal–organic frameworks (MOFs) are a peculiar class of multidimensional materials that can be employed as a photocatalyst to decompose antibiotics present in the wastewater discharged. Herein, a stable Cd(II)-based metal–organic framework with the composition {[Cd₄(L)₂(dib)(H₂O)₃]·H₂O}_n (1), (H₄L = 3-(2,4-di-carboxyphenoxy)phthalic acid, dib = 1,4-bis(1-imidazolyl)benzene) has been synthesized hydrothermally and characterized. The single-crystal X-ray diffraction results indicate that 1 is a 3D 8-connected uninodal net with the point (3⁶·4¹⁸·5³·6). Further, 1 was employed as a catalyst for the oxidation of antibiotics viz. ornidazole (ODZ), nitrofural (NZF), and oxytetracycline (OXY) in an aqueous medium, amongst which the MOF exhibited the best photocatalytic decomposition performance against OXY. The plausible photocatalytic mechanism has been explained with the help of density of states calculations and Hirshfeld surface analysis.