The effect of size and size distribution on the oxidation kinetics and plasmonics of nanoscale Ag particles

Abstract

We employed a simple and effective electroless (EL) plating approach to produce silver nanoparticles (NPs) on bare silicon, on dielectric ZnO nanowires (NWs) and on Si NWs, respectively. The surface stability of the homogeneous Ag NPs formed on the ZnO NW surfaces was investigated by surface enhanced Raman spectroscopy (SERS), which show that the attachment of thiol to the Ag surface can slow down the oxidation process, and the SERS signal remains strong for more than ten days. To further examine the Ag NP oxidation process in air, the oxygen content in the silicon nanowire core/Ag sheath composites was monitored by the energy dispersive x-ray (EDX) method. The amount of oxygen in the system increases with time, indicating the silver NPs were continuously oxidized, and it is not clear if saturation is reached in this time period. To investigate the influence of the Ag NPs size distribution on the oxidation process, the oxygen amount in the NPs formed by EL deposition and e-beam (EB) evaporation on a bare silicon surface was compared. Results indicate a faster oxidation process in the EL formed Ag NPs than those produced by EB evaporation. We attribute this observation to the small diameter of the EL produced silver particles, which results in a higher surface energy.

Morphology and optical absorption change of Ag/SiO2 core-shell nanoparticles under thermal annealing

“…[17][18][19] Besides, it is very important to note that due to the inherent nature of silver, the Ag surface is easily oxidized to AgO x in the air, especially at high temperature. 6 This would lead to a larger environmental dielectric constant and cause a red-shift of the Ag/SiO absorption band. 19 However, AgO x is thermodynamically unstable and would dissociate into Ag and O 2 above about 300 C, 20,21 and the attachment of SiO 2 shell to the Ag surface could slow down the oxidation processes and improve the stability of Ag nanoparticles, which has been testified in the field of catalysis and energy conversion when using such core shell materials instead of bare metal particles.…”

Luminol Chemiluminescence Catalyzed by Silver Nanoparticles for the Sensitive Determination of Penicillamine

“…This signals the formation of AgNPs. Strong reducing agents favors the formation of smaller nanocrystals due to the fast rate of reaction [10,41]. Further, AgNPs of different sizes and shapes were obtained by controlling the number of seeds in the solution.…”

“…In presence of silver seed further reduction of silver ions results in particle growth which was inferred from a noticeable change of color of the solution. Because of the catalytic effect of silver seed secondary nucleation of AgNPs is prohibited which leads to growth of particles [41,42]. Figure 3 shows a typical TEM image of Ag-nanostructures.…”

Re-print of “Sub-eV Ion Deposition Utilizing Soft-Landing Ion Mobility for Controlled Ion, Ion Cluster, and Charged Nanoparticle Deposition”

“…This technique has also been employed for creating self-assembled monolayer (SAM) surfaces that can be reused for SERS analysis [25]. Silver is prone to oxidation and generally requires stabilizers to be used for nanoparticle formation, however soft-landing allows for deposition of silver directly onto the sample [26][27][28][29][30][31][32][33]. This avoids the need for stabilizers and the more common and time consuming solution based synthesis [34][35][36][37].…”