Synthesis of CuO and Cu3N Nanoparticles in and on Hollow Silica Spheres

Copper oxide nanoparticles within hollow mesoporous silica spheres were prepared by binding/adsorbing Cu2+ or [Cu(NH3)4(H2O)2]2+ ions on the surface of carbon spheres, followed by formation of a mesoporous silica shell by sol-gel processing and calcination in air. The CuO nanoparticles can subsequently be converted into Cu3N nanoparticles by nitridation with ammonia. The effect of the different copper precursors, i.e. Cu2+ and [Cu(NH3)4(H2O)2]2+, on the nanocomposites was studied. CuO nanoparticles on the outer surface of hollow silica spheres were obtained by thermal treatment of hollow CuSiO3 spheres in air. Nitridation of the CuSiO3 spheres with ammonia resulted in Cu3N@SiO2 composites, with aggregated Cu3N nanoparticles on hollow silica spheres.