Investigation of catalytic potential of sodium dodecyl sulfate stabilized silver nanoparticles for the degradation of methyl orange dye

Abstract

Sodium dodecyl sulfate (SDS) was employed as a stabilizing agent for the preparation of Ag-NPs while using AgNO3 salt as a source of silver ions and sodium borohydride as a reducing agent in an aqueous medium. Synthesized sodium dodecyl sulfate stabilized silver nanoparticles (Sd@Ag-NPs) were extensively characterized by FTIR, UV–Vis spectroscopy, SEM, XRD and DLS analysis. After that, Sd@Ag-NPs particles were employed as an active catalyst for the reduction of methyl orange (MO) and Rhodamine B (Rh-B) dyes. At first, reduction of MO was carried out in the presence of a catalyst and an excessive amount of NaBH4 in water medium. Reduction of MO was completed in 21 min while the value of apparent rate constant (kapp) was found as 0.385 min −1. Reduction of Rh-B was completed in 15 min with the value of kapp found as 0.131 min−1. Controlled reactions were also performed for the reduction of MO in the absence of catalyst and in the absence of NaBH4 to check the kinetic feasibility of the reaction as well as to check either the decrease in absorbance value was due to the adsorptive action of Sd@Ag-NPs or its working as a catalyst. It was concluded that MO reduction was completed in feasible time in the presence of catalyst. The activity of 9 months old catalyst was slightly decreased as compared to the freshly prepared catalyst for the reduction of MO under same reaction conditions. It was also concluded that Sd@Ag-NPs catalyst successfully degraded the MO dye in the presence of another toxic dye Rh-B in a feasible time. It indicates that our reported Sd@Ag-NPs catalyst can simultaneously reduce the mixture of dyes.