Lithium dodecyl sulphate assisted synthesis of Ag nanoparticles and its exploitation as a catalyst for the removal of toxic dyes

Abstract

We established for the first time the dual significance of lithium dodecyl sulphate (LDS) as a reducing agent as well as a stabilizing agent in the synthesis of silver nanoparticles (Ag NPs). This is an eco-friendly and economical method which avoids the utilization of additional external reducing agent, external stabilizing agent, template and solvent. The size and morphology of the individual Ag NPs can be tuned by controlling the various reaction parameters, such as temperature, concentration and pH. The studies showed that with increase in concentration, not only the size but also the morphology of the Ag NPs changes (from particles to rod). The size of the Ag NPs increased with increase in temperature and pH. The prepared Ag NPs were characterised by ultraviolet–visible spectroscopy (UV–vis), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and X-ray diffraction (XRD) analyses. The probable mechanism for the formation of Ag NPs is presented. The formation of Ag NPs was also studied as a function of time. The synthesised Ag NPs were used for the catalytic reduction of methylene blue and eosin dyes in aqueous media and methylene blue in micellar media. They exhibited good catalytic reduction ability towards methylene blue and eosin dyes in aqueous and micellar media. The probable mechanism for the reduction of dyes is also presented in this article.