Preparation of cuprous oxides with different sizes and their behaviors of adsorption, visible-light driven photocatalysis and photocorrosion

摘要

Cuprous oxide (Cu_2O) nanoparticles and microparticles have been prepared by liquid phase chemical synthesis. The samples were characterized by means of SEM, XRD, UV/DRS and XPS. It was presented that as-prepared Gu_2O nanoparticles are substantially stable in ambient atmosphere and the Cu~(2+) as main state exists on the surface of Cu_2O nanoparticles. As-prepared Cu_2O microparticles can exist stably as a Cu_2O/ CuO core/shell structure, and the Cu~(2+) as main state exists on the surface of Cu_2O microparticles. The behaviors of adsorption, photocatalysis and photocorrosion of Cu_2O particles with different sizes were investigated in detail. The results show that Cu_2O nanoparticles are very easy to photocorrosion during the photocatalytic reaction, which cannot be used as photocatalyst directly to degrade organic compound, although as-prepared Cu_2O nanoparticles exhibit special property of adsorption. Cu_2O microparticles have a higher photocatalytic activity than Cu_2O nanoparticles because of its slower photocorrosion rate, although Cu_2O microparticles have much lower adsorption capacity than Cu_2O nanoparticles. The mechanisms of photocatalysis and photocorrosion for Cu_2O under visible light were also discussed.