Syntheses, structures and photocatalytic properties of three Cd(II) coordination polymers induced by the dicarboxylate regulator

Three new Cd(II) coordination polymers, with formula {[Cd(bb)(CHDA)]·2H2O}n (1), {[Cd4(bb)4(NO3)4(NPA)2]·4H2O}n (2) and [Cd3(bb)4Cl6]n (3) (bb = 4,4′-bis(imidazolyl) biphenyl; H2NPA = 1,4-naphthalenedicarboxylic acid and H2CHDA = 1,4-cyclohexanedicarboxylic acid) have been synthesized hydrothermally by changing the nature of dicarboxylate regulator. The dicarboxylate regulator affects on the binding degree of nitrate and resulted in the formation of the two different 2D layer networks in polymers 1 and 2, while 3 comprising only bb ligand exhibits 2D double-layered structure. All the CPs have been used as photocatalyst for photodegradation of antibiotic nitrofurantoin (NFT) and CPs 1, 2 and 3 show excellent photocatalytic properties degradation efficiency of 95.51 %, 87.48 % and 79.28 % after 20 min under illumination by UV light. Also, to evaluate the possible photocatalytic mechanism and variations in the photocatalytic performances of CPs, band gap simulations have also been carried out.