Electrochemical investigation of copper oxide films formed by oxygen plasma treatment

• Published in: Journal of applied electrochemistry Vol. 27; no. 4; pp. 414 - 421
• Main Authors: BELLAKHAL, N, DRAOU, K, BRISSET, J. L
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-04-1997
• Subjects: Chemistry; Electrochemistry; Exact sciences and technology; General and physical chemistry; Kinetics and mechanism of reactions; Copper Oxides; Chemical reduction; Reaction mechanism; Transition metal; Copper; Sheet electrode; Experimental study; Electrochemical reaction; Inorganic compound
• ISSN: 0021-891X; 1572-8838
• DOI: 10.1023/A:1018409620079

Linear potential sweep voltammetry was used to characterize the copper oxides grown on a metal substrate when exposed to a low pressure inductively coupled oxygen plasma. This study confirms the formation of a precursor oxide Cu sub x O (x > 4), two copper(I) oxides Cu sub 2-x O and Cu sub 3 O sub 2 , and copper(II) oxide CuO. The electrochemical reduction curve of Cu sub x O is characterized in aqueous solution (pH 9.2) by a minor peak near -0.5 versus, SCE while the two Cu(I) oxides present one reduction peak at -0.8 V versus SCE and cannot be electrochemically separated; CuO is reduced to Cu(I) at -0.65 V versus SCE. The reduction potentials of the copper(I) and copper(II) oxides vary with the oxide layer thickness which increases with the time of exposure to the plasma and the injected electric power and decreases as the distance between the sample and the first coil increases for given treatment parameters. In addition, a mechanism is proposed for the reduction of thin films containing the copper(I) and copper(II) oxides formed after plasma treatment.