Water Vapor Effects on Formation Process of NiO/Si0₂ Particles by CVD

Abstract

When NiO/SiO₂ particle is produced by simultaneous oxidation of NiCl₂ and SiCl₄ with air, the conversion of NiCl₂ to nickel oxide is low, and NiCl₂ remains in the NiO/SiO₂ specimen.
Water vapor was added as a promoter of the oxidation to diminish the NiCl₂ in the particles produced. The reaction scheme with water addition was examined thermodynamically and it was revealed that the reaction proceeded by scheme 2. It was also found by inspection of temperature-programmed reduction (TPR) spectra that the addition of water enhanced the interaction between NiO and SiO₂.