As Catalytic as Silver Nanoparticles Anchored to Reduced Graphene Oxide: Fascinating Activity of Imidazolium Based Surface Active Ionic Liquid for Chemical Degradation of Rhodamine B

Abstract

A kinetic study, first of its kind, regarding the catalytic activity of imidazolium-based surface-active ionic liquid (SAIL) viz. 1-dodecyl-3-methyl imidazolium chloride ([DDMIM][Cl]) toward the reductive degradation of a model cationic dye viz. rhodamine B (RhB) is presented. The catalytic activity of the pre and post micellar concentrations of SAIL [DDMIM][Cl], its conventional analogue surfactant dodecyltrimethylammonium bromide ([DTAB]) and silver (Ag) nano-particles anchored to the reduced graphene oxide (Ag-rGO) toward reductive degradation of RhB was explored. The catalytic activity observed for the [DDMIM][Cl] is much better than that of DTAB and is almost comparable to the activity exhibited by Ag-rGO. The catalytic rate constants (kcat) estimated in presence of pre-micellar concentrations of [DDMIM][Cl] (10 mM), DTAB (12 mM) and in presence of Ag-rGO as catalyst were found to be 11.48 × 10−2 min−1, 3.4 × 10−2 min−1 and 14.35 × 10−2 min−1 respectively. The results clearly establish the fascinating catalytic activity (almost comparable to that exhibited by Ag-rGO) of [DDMIM][Cl] for the reductive degradation of a widely used carcinogenic, mutagenic and toxic organic dye of great environmental concern. The presented results are expected to stimulate intense research activities that may uncover new opportunities toward exploitation of the catalytic activity of aqueous SAIL solutions. Surface active ionic liquid [DDMIM][Cl] is significantly more active than its conventional analogue DTAB and almost as active as Ag-rGO in facilitating the NaBH4 assisted chemical degradation of rhodamine B (RhB)-one of the most carcinogenic, mutagenic and toxic organic dyes.