Preparation and Characterization of Silver Nanoparticles and their Use in Catalytic Reduction of 4-Nitrophenol

Silver nanoparticles of various sizes were prepared at room temperature using silver nitrate as a precursor, various molar ratios of sodium citrate as a surfactant stabilizing material and sodium borohydride as a reducing agent. The morphology, distribution and sphericity of the particles were assessed in images from a transmission electron microscope (TEM). The sizes of the particles were calculated as being 9, 11 and 14 nm. The effects of the particles’ sizes on the plasmon bands were confirmed by ultraviolet-visible spectra measurements. The prepared samples were applied in photo catalysis of 4-Nitrophenol (4-NP), and the rate constant was determined as 0.05 s-1, 0.0015 s-1 and 0.00021 s-1 for particles of 9 nm, 11 nm and 14 nm, respectively. Due to their high surface energy, the smaller particle sizes were more active in the photo catalytic application.