Complexes of Cu(II) with polyvinyl alcohol as precursors for the preparation of CuO/SiO₂ nanocomposites

Abstract 

Cupric oxide (CuO) nanoparticles have been prepared in amorphous SiO₂ matrix using a novel variant of sol-gel technique. The method is based on the polycondensation of a silica source (sodium silicate) in the presence of an aqueous solution containing complex of Cu(II) with polyvinyl alcohol (CuPVA). After gelation, polymeric complexes containing several thousands Cu atoms each are incorporated into the silica network forming a precursor, which is then annealed in oxygen to get rid of organic components. The formation of CuO nanoparticles was confirmed by electron diffraction studies. The size of nanoparticles can be controlled by varying [Cu²⁺]/[PVA] ratio in the precursor. Thus prepared CuO/SiO₂ nanocomposites are characterized by high specific surface area as measured by capillary adsorption of nitrogen, suggesting their possible use in catalysis.