Pd on poly(1-vinylimidazole) decorated magnetic S-doped grafitic carbon nitride: an efficient catalyst for catalytic reduction of organic dyes

A novel magnetic catalyst, (SGCN/Fe3O4/PVIs/Pd) was synthesized by growing of poly(1-vinylimidazole) on the surface of ionic liquid decorated magnetic S-doped graphitic carbon nitride, followed by stabilization of palladium nanoparticles. Catalytic activity of the prepared heterogeneous catalyst was explored for the catalytic reduction of hazardous dyes, methyl orange and Rhodamine B, in the presence of NaBH4. Besides, the effects of the reaction variables on the catalytic activity were investigated in detail. The kinetics study established that dye reduction was the first order reaction and the apparent activation energy was calculated to be 72.63 kJ/mol and 68.35 kJ/mol(1) for methyl orange and Rhodamine B dyes, respectively. Moreover, Delta S-# and Delta H-# values for methyl orange were found to be - 33.67 J/mol K and 68.39 kJ/mol respectively. These values for Rhodamine B were - 45.62 J/mol K and 65.92 kJ/mol. The recycling test verified that the catalyst possessed good stability and reusability, thereby making it a good candidate for the catalytic purposes. Furthermore, a possible catalytic mechanism for dye catalytic reduction over SGCN/Fe3O4/PVIs/Pd was proposed.