Stability and Reactivity: Positive and Negative Aspects for Nanoparticle Processing

Describing inorganic nanoparticles in the context of surface reactivity and catalysis

Fabrication of inorganic nanoparticles is now a mature field. However, further advances, in particular in the field of catalysis, require a more accurate description of their surface and of the transformations occurring beneath the surface in the environment of use. Through a selection of case studies, this feature article proposes a journey from surface science to nanoparticle design, while illustrating state-of-the-art spectroscopies that help provide a relevant description of inorganic nanoparticles in the context of surface reactivity.

Facile Synthesis of Monodisperse Silver Nanospheres in Aqueous Solution via Seed-Mediated Growth Coupled with Oxidative Etching

Because of their perfect geometrical symmetry, spherical metal nanoparticles have attracted much attention for various applications, including fundamental studies and construction of plasmonic devices. In this work, monodisperse silver nanospheres (Ag NSs) in aqueous solution were directly prepared by a continuous process of seed-mediated growth followed by oxidative etching. Silver nanocubes (Ag NCs) were synthesized by a seed-mediated growth method and subsequently were transformed to Ag NSs by simple injection of Cu²⁺ to the freshly prepared Ag NCs solution. Not requiring any centrifugation steps at both growth and etching stages makes this procedure convenient and efficient. The etching process and morphology evolution of silver nanostructure were monitored by UV-vis spectromater, SEM, and XRD. Monodisperse Ag NSs with broadly tunable diameters (from 37 to 68 nm) have been successfully prepared. The optical property of Ag NSs has been studied and the experimental results show fairly good consistency with simulation results. Furthermore, these Ag NSs prepared by our approach could be constructed into ordered superlattice by self-assembly technique based on their high monodispersity and sphericity.

Anomalous effect of the aging degree on the ionic permeability of silica shells

We discovered an anomalous effect of the aging degree on the ionic permeability of colloidal silica.