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

Abstract

Abstract In the present work, a new kind of magnetic hybrid based on a unique sulfur rich cadmium coordination polymer (CdII-CP) has been prepared with a facile and efficient method via ultrasonic condition. The nano-structure of CdII-CP namely, [Cd (SCN)2L]n [where L = 1, 1-(1,4-butanediyl)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 01) plane. The CdII centers adopt a trigonal bipyramidal geometry which is an uncommon core for a cadmium CP with CdS3N2 nodes. We have immobilized the CdII-CP with CoFe2O4 nanoparticles to build up CdII-CP @CoFe2O4 and CoFe2O4 @CdII-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 CdII-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 CdII-CP shows more photoresponse than the bulk CdII-CP .The direct excitation of nodes within the CdII-CP caused an electron transfer which is responsible for the photocatalytic degradation of dyes. A close inspection on the structure of CdII-CP revealed that the presence of nodes greatly improved the electron–hole separation and effectively convert the photo generated active ·OH radicals.