CTAB capped synthesis of bio-conjugated silver nanoparticles and their enhanced catalytic activities

Silver nanoparticles (AgNPs) were synthesized via green route with the aid of Pithecellobium dulce pod mesocarp aqueous extract. The appearance of the yellow color with surface plasmon resonance band at ca. 400–450nm in UV–visible spectroscopy reveals the formation of AgNPs. The morphology of AgNPs strongly depends on the cetyltrimethylammonium bromide (CTAB). Transmission electron microscope (TEM) and scanning electron microscope (SEM) were used to determine the size, shape and the size distribution of AgNPs. To overcome the serious problems related to environment like discharge of hazardous dyes to water bodies, AgNPs have been found to be very important catalyst for the degradation of methyl orange (MO) and eosin yellow (EY) in presence of NaBH4. The pseudo-first order rate constant, activation energy, turnover frequency were found to be 2.2×10−3s−1, 49.7kJmol−1, 1.2×10−3s−1 and 1.4×10−3s−1, 55.1kJmol−1, 0.8×10−3s−1, respectively, for methyl orange and eosin yellow degradation catalyzed by AgNPs.