In Situ One-Pot Synthesis of 1-Dimensional Transition Metal Oxide Nanocrystals

One-dimensional colloidal metal oxide nanocrystals are of great importance in materials chemistry, but reports on these materials are rare due to lack of well-defined synthetic protocols. In this paper, we present a general and highly effective one-pot synthetic protocol to produce 1-dimensional nanostructures of transition metal oxide (e.g., W18O49, TiO2, Mn3O4, and V2O5) through thermally induced crystal growth processes from a mixture of metal chloride and surfactants

Redox−Transmetalation Process as a Generalized Synthetic Strategy for Core−Shell Magnetic Nanoparticles

Although multicomponent core−shell type nanomaterials are one of the highly desired structural motifs due to their simultaneous multifunctionalities, the fabrication strategy for such nanostructures is still in a primitive stage. Here, we present a redox−transmetalation process that is effective as a general protocol for the fabrication of high quality and well-defined core−shell type bimetallic nanoparticles on the sub-10 nm scale. Various core−shell type nanomaterials including Co@Au, Co@Pd, Co@Pt, and Co@Cu nanoparticles are fabricated via transmetalation reactions. Compared to conventional sequential reduction strategies, this transmetalation process has several advantages for the fabrication of core−shell type nanoparticles:  (i) no additional reducing agent is needed and (ii) spontaneous shell layer deposition occurs on top of the core nanoparticle surface and thus prevents self-nucleation of secondarily added metals. We also demonstrate the versatility of these core−shell structures by transferring Co@Au nanoparticles from an organic phase to an aqueous phase via a surface modification process. The nanostructures, magnetic properties, and reaction byproducts of these core−shell nanoparticles are spectroscopically characterized and identified, in part, to confirm the chemical process that promotes the core−shell structure formation