• Durante, Christian
• Colazzo, Luciano
• Chirkov, Dymitrov
• Giallongo, Giuseppe
• Gennaro, Armando
• Zheng, Jian
• Granozzi, Gaetano
• Zanatta, Michele
• Calvillo, Laura
• Marega, Carla
• Rizzi, Gian Andrea

Abstract

u 2 O nanoparticles have been grown by pulse-electrochemical deposition on a Digital Versatile Disk (DVD) which acts as a nanostructured electrode. Prior to Cu 2 O deposition, the silver-coated rectangular-shaped grooves of the disassembled DVD were coated with a TiO 2 thin film by a modified sol–gel method, where oxalic acid is used in place of the usual mineral acids to peptize the precipitated hydrous titania formed from the hydrolysis of titanium iso-propoxide. This procedure leaves no inorganic residues after UV-curing, resulting in a high quality film, mainly composed of TiO 2 -anatase. As demonstrated by Atomic Force Microscopy (AFM) measurements, the DVD grooves are filled by a 120–130 nm thick TiO 2 film, while the thickness of the TiO 2 deposit on the crests is only ca. 50 nm. This inhomogeneous thickness leads to an inhomogeneous electric field when the DVD is used as an electrode for depositing Cu 2 O nanoparticles, which eventually leads to the growth of Cu 2 O nanoparticles only on the DVD crests. A highly regular and reproducible Cu 2 O/TiO 2 stripe-like heterostructure is obtained where both semiconducting oxides are aside. This system has been characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), X-ray photoemission spectroscopy (XPS), Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectroscopy, Raman spectroscopy and photocurrent measurements. A possible use of this easy & cheap electrode as a visible light responsive sensor to water soluble organics in basic solution is suggested.

Topics

• nanoparticle
• Deposition
• impedance spectroscopy
• mineral
• silver
• scanning electron microscopy
• thin film
• x-ray photoelectron spectroscopy
• atomic force microscopy
• titanium
• Raman spectroscopy
• curing