Growing Small Silver Particle as Redox Catalyst

Abstract

Growing small particles of silver have been observed to be more efficient catalysts than stable colloidal particles. These growing particles catalyze the borohydride reduction of several organic dyes. The rate of the reduction catalyzed by growing particles is distinctly faster compared to that of stable and larger silver particles, which are the final products of growing particles. Catalysis is due to efficient particle-mediated electron transfer from the BH4- ion to the dye. The catalytic activity of the particles depends on their size, E1/2 of the dye, and the dye−particle interaction. The presence of surfactant influences the catalytic property of the particles by controlling their growth, by inhibiting adsorption of reactants/products onto the particle surface, and by specific dye−surfactant interaction.