Solution synthesis of Cu2O/TiO2 core-shell nanocomposites

We report here a simple approach to the synthesis of Cu2O/TiO2 core-shell nanocomposites with uniform octahedral structure in solution phase. First, fresh synthesized Cu2O octahedra were used as precursor, and butyl titanate (Ti(OBu)(4)) diluted by ethanol was preliminary hydrolyzed by the water adsorbed on the surface of Cu2O, so a very thin TiO2 condensed on the Cu2O surfaces. Then, when a mixture of water and ethanol was dropped into the reaction system, the Ti(OBu)(4) would further hydrolyze and condense around the Cu2O to form TiO2, so octahedral Cu2O/TiO2 core-shell composites with uniform and compact TiO2 shells were obtained. This method is suitable for the formation of uniform integrated TiO2 shells and their thickness can be controlled by adjusting the ratio of water/ethanol (W/E). According to the surface photovoltage spectroscopy of the Cu2O/TiO2 composites, we think the material would have a potential application in photocatalysis and photoelectric transition. (C) 2009 Elsevier B. V. All rights reserved.