The Development and Applications of Novel, Hybrid Niobium Pentoxide Nanocomposites in Photocatalysis

点击翻译按钮获取中文摘要

Due to the high abundance of niobium (Nb) and >99% of the total worldwide Nb production found jointly between Canada and Brazil, finding new applications for niobium-based materials benefits both economies by creating new collaborative markets and technologies. Namely, heterogeneous catalysis is of particular interest as the remarkable chemical versatility of Nb2O5 allows for use not only as well-known Bronsted and Lewis acid catalysts, but also presents an opportunity for development of its understudied photocatalytic and supramolecular properties.******Noble metal nanoparticles, in particular gold (AuNP), have garnished attention as catalysts in a number of organic reactions. Recent work has focused on the photochemical generation of AuNP, resulting in nanomaterials with exceptional stability and small size distribution, ideal for catalytic testing. In lieu of typical, bench-top catalysis, exploitation of the surface resonance properties of AuNP presents the opportunity to study the catalysis of various organic reactions, using "greener" photochemical methodologies and introducing visible light as an integral reaction participant. AuNP possess an easily identifiable absorption in the visible region of the electromagnetic spectrum, termed the surface plasmon band (SPB). SPB AuNP excitation has been shown to induce catalytic reactions by way of localized heating of the nanoparticle surface, as well as electron transfer pathways.*** ***The proposed research aims to draw on the suggested photocatalytic abilities of niobium oxide and niobium oxide salts as potential photocatalytic alternatives to TiO2-derived catalysts. Though still able to be excited within the UV region of the spectrum, modifying niobate semiconductor supports with AuNP is attractive for potentially improved photo-induced reduction performance. AuNP incorporation into the niobate structure will extend the absorption of light into the visible region of the electromagnetic spectrum to include that of solar energy (a highly desired property for energy conservation measures), and may also be used to improve the photocatalytic properties of the nanomaterial itself by maximizing photoinduced charge separation. Moreover, the intrinsic photocatalytic characteristics of AuNP supported on layered niobate guest-host systems may also be of considerable interest in regards to the development of novel sensitized materials for energy storage.  These unique supramolecular structures may be useful for examining the effects of molecular confinement on catalytic reactions and also be beneficial towards investigating the electron transport capabilities of supramolecular niobate-derived supports, favorable in energy storage/conversion and renewable energy research.  Most importantly, this research will examine the light-induced chemical properties of an abundant, and uniquely Canadian, global resource.**************