A new 3D Cd(II) metal organic framework (MOF) as an efficient photocatalyst for nitrofurantoin antibiotic degradation

Abstract

A new Cd(II)-based MOF with composition [Cd3(bpyp)3(HCOO)4(H2O)2·2NO3−]n (1) (bpyp = 2,5-bis(pyrid-4-yl)pyridine) have been synthesized and characterized by single crystal X-ray diffraction and FTIR spectroscopy. The MOF 1 forms 3D framework comprising elliptical channels of size 5.1×8.8 Å along the c-axis and possess (3,4,5)-connected topology. The MOF have been employed as catalyst for photodegradation of antibiotics such as nitrofurantoin (NFT), nitrofurazone (NFZ) and furazolidone (FZD). Amongst, these antibiotics, the MOF exhibits best photocatalytic degradation of NFT upto to ∼99.66% in 1 h. The photocatalytic efficacy of MOF 1 against antibiotics follows the order NFT > NFZ > FZD. The impact of NFT concentration as well as photocatalyst dosage on catalytic efficacy of 1 have been explored. These experiments suggest that most appropriate reaction conditions for 1 assisted photodecomposition of NFT are 5 mg dose of 1 and 40 ppm starting NFT amount. The reactive oxygen species (ROS) quenching experiments suggest that superoxide (O2·−) is majorly responsible for NFT decomposition. The plausible mechanism employing which the MOF 1 photodegrades NFT has been explained by density of states plot and Hirshfeld surface analysis. Further, LCMS studies have been performed to explore the possible intermediates formed during photodegradation of NFT.