A new magnetic hybrid based on a unique sulfur rich cadmium coordination polymer used for high selective photocatalytic degradation of cationic dyes

In the present work, a new kind of magnetic hybrid based on a unique sulfur rich cadmium coordination polymer (Cd-II-CP) has been prepared with a facile and efficient method via ultrasonic condition. The nano-structure of Cd-II-CP namely, [Cd (SCN)(2)L](n) [where L=1, 1-(1,4-butanediy1)bis(1,3-dihydro-3-methyl-1H-imidazole-2-thione] has been synthesized and fully characterized. The X-ray analysis shows the formation of an undulated polymeric two-dimensional network parallel to the (0 0 1) plane. The cd(II) centers adopt a trigonal bipyramidal geometry which is an uncommon core for a cadmium CP with CdS3N2 nodes. We have immobilized the Cd-II-CP with CoFe2O4 nanoparticles to build up Cd-II-CP @CoFe2O4 and CoFe2O4 @Cd-II-CP hybrids by sonochemical procedure. The photocatalytic efficiency was tested by monitoring the photocatalytic oxidation of cationic and anionic dyes under ultraviolet irradiation. In the dark condition, the Cd-II-CP shows a selective adsorption of anionic dye, while adsorption of the cationic dyes were negligible. Consequently, two independent studies have been performed. For the anionic dye adsorption/desorption behavior were examined, while for the cationic dyes, photo degradation phenomena was investigated. It is worth to note that the nanostructure of Cd-II-CP shows more photoresponse than the bulk Cd-II-CP .The direct excitation of nodes within the Cd-II-CP caused an electron transfer which is responsible for the photocatalytic degradation of dyes. A close inspection on the structure of Cd-II-CP revealed that the presence of nodes greatly improved the electron-hole separation and effectively convert the photo generated active center dot OH radicals. (C) 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.