Synthesis of Metal and Metal Oxide Nanoparticles Encapsulated in Electron-Conductive Hollow Three-Dimensional Inorganic Structures

摘要

Nanoporous materials have attracted substantial interest due to the wide range of applications of these materials in sensing, catalysis, electrocatalysis, water purification, separation, and energy conversion and storage. There is a persistent need for the development of new heterogenous catalysts, fuel cell cathode materials and materials for Li-ion battery electrodes to address some of the problems encountered with state-of-the-art materials, such as the ionomer poisoning of the polymer electrolyte membrane fuel cell (PEMFC) cathode catalysts and sintering and aggregation of heterogeneous catalysts. This talk introduces a new class of sintering and aggregation-resistant materials termed "metal and metal oxide nanoparticles encapsulated in electron-conductive hollow 3D inorganic structure" for electrocatalysis and energy storage applications. The developed synthetic strategy is generic, reliable, and scalable. It is a combination of seed-mediated growth, sol-gel chemistry, and chemical vapor deposition (CVD). The prepared nanomaterials are electron conductive and have yolk-like structure. They serve as nanoreactors and have been proven to be accessible to reactant molecules in gaseous and liquid phases and sinter resistant. The electronic structure of the conductive layer has been identified by means of electron energy loss spectroscopy (EELS), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA) to be graphene-like structure with sp~2 hybridized bonds.