Of particular interest to the preparation of advanced catalytic materials is efficient utilization of carbon nanostructures and noble metal nanoparticles, their stabilization and intentional activation, as well as organization into two-dimensional arrays, ultra-thin films or three-dimensional networks (e.g. through sequential attraction) on electrode surfaces. They can form nanosized materials with well-defined composition, structure and thickness that exhibit desirable electrocatalytic properties (e.g. toward reduction of CO2
). We explore here the ability of polynuclear inorganic systems to stabilize and derivatize metal and carbon nanostructures. Here certain nanostructured metal oxides of zirconium, titanium, zinc or tungsten have been demonstrated to influence supported metal centers in ways other than simple dispersion over electrode area. Evidence is presented that the support can modify activity (presumably electronic nature) of catalytic metal nanoparticles (e.g. Cu, Ag, Au, Pd, Pt or Ru) thus affecting their chemisorptive and catalytic properties. Metal oxide nanospecies can generate –OH groups at low potentials that induce proton mobility at the photo(electro)chemical interface.
Our research interests concern development of systems for the reduction (conventional/electrocatalytic or photoelectrochemical) of carbon dioxide. For example, nanosized Cu or Au naoparticles immobilized within ultra-thin films of tungsten oxide or zirconia have been considered. Reduction of carbon dioxide begins now at less negative potentials and is accompanied by significant enhancement of the CO2-reduction current densities.
When it comes to photoelectrochemical reduction, we are also going to demonstrate utility of zirconia or zinc oxide over-layers on copper(I) oxide photocathodes irradiated with visible light in aqueous solutions. The possibility of generation of localized surface plasmons with use of gold or silver nanoparticles, will also be considered. Special attention will be paid to stability and controlled reactivity of the proposed systems.