Synthesis and Catalytic Application of Nanostructured Silver Dendrites

Abstract

We demonstrate a simple templateless and surfactant-free wet-chemical method of preparing silver (Ag) nanostructures with different dendritic morphologies at room temperature. This has been accomplished by aging the aqueous mixture of AgNO3 and citrate salts, carrying different cations for different time periods. Transmission electron microscopic (TEM) and X-ray diffraction (XRD) studies confirmed the formation of single-crystalline dendritic Ag nanostructures. It has been found that the nature and the concentration of citrate salt have a significant effect on the morphology of the formed Ag nanostructures. A possible formation mechanism has also been discussed on the basis of monitoring the surface plasmon resonance properties and TEM images with time during the course of formation of silver dendrites. The formed dendritic silver nanostructures showed excellent catalytic activity in the borohydride reduction of p-nitrophenol to p-aminophenol compared to the spherical silver nanoparticles.

Natural reducing agents for electroless nanoparticle deposition: Mild synthesis of metal/carbon nanostructured microspheres

“…5a shows time-dependent UV-Vis spectra of Ag/CM aqueous suspensions containing 1.010 -2 NaBH 4 , after injection of 4-nitrophenol; spectra have been corrected by the scattering contribution in the microsphere suspension [56]. A maximum at 400 nm is characteristic of 4-nitrophenolate ions [54,55,57,58]; the peak decreased rapidly after injection into the Ag/CM : NaBH 4 suspension, indicating that the arylnitro group is consumed over time. The graph also shows the appearance of a peak at 290 nm, which is attributed to the formation of 4-aminophenol [54,55,57,58], thus confirming that the nitroaromatic compound is reduced to its corresponding arylamine.…”

“…A maximum at 400 nm is characteristic of 4-nitrophenolate ions [54,55,57,58]; the peak decreased rapidly after injection into the Ag/CM : NaBH 4 suspension, indicating that the arylnitro group is consumed over time. The graph also shows the appearance of a peak at 290 nm, which is attributed to the formation of 4-aminophenol [54,55,57,58], thus confirming that the nitroaromatic compound is reduced to its corresponding arylamine. Control experiments confirmed that no reduction takes place in the presence of NaBH 4 or carbon microspheres alone, but only when Ag/CM composite particles were used in suspension.…”

“…If NaBH 4 is in excess with respect to 4-nitrophenol then its concentration can be assumed constant and the reaction rate becomes pseudo-first-order in the concentration of 4-nitrophenol [22,23,54,[57][58][59]. Fig.…”

“…An apparent rate coefficient k app was calculated near time zero from linear fits of curves such as the one in Fig. 5b [54,[57][58][59], yielding k app = 0.0015  0.0002 s -1 .…”

A Systematic Search for Structures, Stabilities, Electronic and Magnetic Properties of Silicon Doped Silver Clusters: Comparison with Pure Silver Clusters

“…In particular, many chemists and physicsts have worked with growing interest on silver and doped silver clusters [3 -7]. The major reason is due to the fact that they exhibit unique size and shape dependence and have promising applications in many areas such as chemical sensing [8], catalysis [9,10], photochemical [11], absorbing organic materials, and heliotechnics [12,13], as well as nanofabrication [14].…”