Cetyltrimethylammonium bromide assisted synthesis of silver nanoparticles and their catalytic activity

Abstract

In this paper we report the shape-directing role of cationic cetyltrimethylammonium bromide (CTAB) surfactant on the morphology silver nanoparticles (AgNPs). UV–visible data reveal that the position of surface plasmon resonance band strongly depends on the [glycine] as well as [CTAB]. The reaction follows pseudo first order kinetics with respect to [glycine]. The position and intensity of absorption band could be tuned by changing [CTAB]. The presence of CTAB was essential for the synthesis of stable prefect transparent yellow colour silver sols at room temperature. The as prepared AgNPs was used as a catalyst for the decolourization of methyl orange. Catalytic efficiency increases with [NaBH4] from 0.0% to fold 90%. The activation energy was found to be 119kJ mol−1 for the degradation of methyl orange, where as we did not observed the degradation of dye with only [NaBH4]. A most plausible mechanism is proposed with the following rate law to the degradation of methyl orange.−dMethyl orangedt=kKCKaKadH+BH4−Methyl orangeTAg0Ka+H+