Synthesis of CuO and Cu 3 N Nanoparticles in and on Hollow Silica Spheres

Copper oxide nanoparticles within hollow mesoporous silica spheres were prepared by binding/adsorbing Cu 2+ or [Cu(NH 3 ) 4 (H 2 O) 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 Cu 3 N nanoparticles by nitridation with ammonia. The effect of the different copper precursors, i.e. Cu 2+ and [Cu(NH 3 ) 4 (H 2 O) 2 ] 2+ , on the nanocomposites was studied. CuO nanoparticles on the outer surface of hollow silica spheres were obtained by thermal treatment of hollow CuSiO 3 spheres in air. Nitridation of the CuSiO 3 spheres with ammonia resulted in Cu 3 N@SiO 2 composites, with aggregated Cu 3 N nanoparticles on hollow silica spheres.