In this work, we reported the synthesis of monodisperse, quasispherical Ag nanoparticles (NPs) with sizes of 40–300 nm by using ascorbic acid reduction of a silver–ammonia complex onto preformed, 23 nm Ag-NP seeds in the aqueous solution with an optimal pH of about 9.6 at room temperature. The as-prepared Ag NPs with such a large size span (from 40 to 300 nm) and high quality by one-pot seeded growth method are reported for the first time to the best of our knowledge. It is found that the key in the present seed-mediated growth method is to introduce a proper amount of ammonia water for the formation of a stable complex with a silver precursor (silver–ammonia complex) while maintaining the pH value of the growth solution simultaneously. By using rhodamine 6G molecules as probes, the surface-enhanced Raman scattering (SERS) activities of the as-prepared Ag NPs in ethanol solution are highly dependent on the sizes of Ag NPs at the fixed 633 nm laser and at the fixed particle number, which show a volcano-like curve. Moreover, 125 nm Ag NPs bear the largest SERS activity among them. Furthermore, Ag NPs with narrow distributions in shape and size (say, less than 10%) can achieve the uniformity and reproducibility of their SERS signals in solution; their relative standard deviations can be as low as 5% in space and temporal scale.

In this work, uniform ultra-small core-shell Au-Pt nanoparticles (denoted as USCS Au-Pt NPs) with Au-decorated Pt surfaces are successfully prepared by Fe(II)-assisted one-pot co-reduction of Au(III) ions and Pt(II) ions...

Au6–50 aerogels with {110}-rich facets (35.5%) are fabricated for glucose detection by size-dependent surface reconstruction between two differently-sized gold nanoparticles.

In this work, macroscopical monolayer films of ordered arrays of gold nanoparticles (MMF-OA-Au NPs) are successfully prepared at the interfaces of toluene-diethylene glycol (DEG) with a water volume fraction of...

In this work, a series of AuPNR 6 – 50 aerogels with different percentages of {110} facets (from ∼12 to 36%) were controllably prepared and then used to investigate their performance (specific activity and long-term stability) toward ethylene glycol oxidation reaction (EGOR), in which PNR represents the particle number ratio of 6 nm Au NPs to 50 nm Au NPs. It is found that their specific activity and long-term stability highly depend on the sum of the percentage of the {100} and {111} facets and the percentage of {110} facets, respectively. In addition, Au24 6 – 50 aerogels with the highest percentage of {110} facets can possess excellent long-term stability (retaining about 95% of the initial current) but still have excellent specific activity (about 90.42 mA cm–2). Thus, the specific activity and long-time stability of AuPNR 6 – 50 aerogels toward EGOR can be well balanced by controlling the proper percentage of {110} facets on their surfaces. Therefore, the successful fabrication of AuPNR 6 – 50 aerogels with greatly improved long-term stability and excellent specific activity not only provides a novel method for the design of electrocatalysts but also would boost the commercial development of direct ethylene glycol fuel cells.