Electrochemical deposition of a single phase of pure Cu2O films by currentmodulation methods

The electrodeposition of cuprous oxide (Cu2O, red copper oxide) on Pt catho de in a weak acidic electrolyte was executed by the current modulation meth od. The formation mechanism of Cu2O was investigated by electrochemical cha racteristics analysis utilizing electrochemical quartz crystal microbalance (EQCM), chronopotentiometry (CP), and pulsed current methods. A scanning e lectron microscope and X-ray diffractometer were also used for investigatio n of the mechanism for Cu2O film growth. EQCM and CP results indicate that the dissolution potentials of Cu and Cu2O were different and were used for the selective dissolution of copper when the pulsed anodic current was appl ied. Pulsed electrodeposition technique offered a useful method in preparin g Cu2O thin film, in which both Cu metal and Cu2O phases were electrodeposi ted on platinum electrode, when a higher cathodic current, -5.0 mA/cm(2), w as constantly applied in a 10 mM copper nitrate solution. The cycling of cu rrent led to the rapid formation of a single phase of Cu2O thin film, which was uniform and compact. (C) 1999 The Electrochemical Society. S1099-0062( 99)08-130-4. All rights reserved.