Novel Nanocrystalline CuO-TiO2 Composite: Electron Injection from CuO to TiO2 illuminating with Visible Light without Polarization Voltage

Abstract

Films of CuO-TiO₂ composite were prepared at room temperature on conducting glass substrates using a novel photodeposition technique followed by temperature annealing in order to completely oxidize all copper species. Films were deposited exploiting TiO₂ photocatalytic properties. Near UV radiation passed through the substrate in contact with an aqueous TiO₂ suspension containing copper(II) nitrate and ethanol in solution. Structures formed by the conducting glass (ITO), the CuO-TiO₂ composite, a hole conducting polymer and a silver contact were assembled. Illuminating this structure, without a bias voltage, a short-circuit photocurrent is produced. Its direction indicates that electrons are injected from the copper oxide to the TiO₂ . This photocurrent dependence with time is analyzed after light is shut off.