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

Cuprous oxide (Cu2O) 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 Cu2O nanoparticles are substantially stable in ambient atmosphere and the Cu+ as main state exists on the surface of Cu2O nanoparticles. As-prepared Cu2O microparticles can exist stably as a Cu2O/ CuO core/shell structure: and the Cu2+ as main state exists on the surface of Cu2O microparticles. The behaviors of adsorption, photocatalysis and photocorrosion of Cu2O particles with different sizes were investigated in detail. The results show that Cu2O nanoparticles are very easy to photocorrosion during the photocatalytic reaction, which cannot be used as photocatalyst directly to degrade organic compound, although as-prepared Cu2O nanoparticles exhibit special property of adsorption. Cu2O microparticles have a higher photocatalytic activity than Cu2O nanoparticles because of its slower photocorrosion rate, although Cu2O microparticles have much lower adsorption capacity than Cu2O nanoparticles. The mechanisms of photocatalysis and photocorrosion for Cu2O under visible light were also discussed. (c) 2008 Elsevier Masson SAS. All rights reserved.