Role of Temperature in the Growth of Silver Nanoparticles Through a Synergetic Reduction Approach

This study presents the role of reaction temperature in the formation and growth of silver nanoparticles through a synergetic reduction approach using two or three reducing agents simultaneously. By this approach, the shape-/size-controlled silver nanoparticles (plates and spheres) can be generated under mild conditions. It was found that the reaction temperature could play a key role in particle growth and shape/size control, especially for silver nanoplates. These nanoplates could exhibit an intensive surface plasmon resonance in the wavelength range of 700–1,400 nm in the UV–vis spectrum depending upon their shapes and sizes, which make them useful for optical applications, such as optical probes, ionic sensing, and biochemical sensors. A detailed analysis conducted in this study clearly shows that the reaction temperature can greatly influence reaction rate, and hence the particle characteristics. The findings would be useful for optimization of experimental parameters for shape-controlled synthesis of other metallic nanoparticles (e.g., Au, Cu, Pt, and Pd) with desirable functional properties

Mesoporous Single-crystal CoSn(OH)6 Hollow Structures with Multilevel Interiors

Hollow nanostructures represent a unique class of functional nanomaterials with many applications. In this work, a one-pot and unusual “pumpkin-carving” protocol is demonstrated for engineering mesoporous single-crystal hollow structures with multilevel interiors. Single-crystal CoSn(OH)(6) nanoboxes with uniform size and porous shell are synthesized by fast growth of CoSn(OH)(6) nanocubes and kinetically-controlled etching in alkaline medium. Detailed investigation on reaction course suggests that the formation of a passivation layer of Co(III) species around the liquid-solid interface is critical for the unusual hollowing process. With reasonable understanding on the mechanism involved, this approach shows high versatility for the synthesis of CoSn(OH)(6) hollow architectures with a higher order of interior complexity, such as yolk-shell particles and multishelled nanoboxes. The obtained CoSn(OH)(6) hollow nanostructures can be easily converted to hollow nanostructures of tin-based ternary metal oxides with excellent photocatalytic and electrochemical properties