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CuO Crystalline Modified Glassy Carbon Electrodes for Anodic Amperometric Determination of Hydrogen Peroxide
Author(s) -
Lin Xiangqin,
Jing Zhenhui
Publication year - 2010
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201190029
Subject(s) - cyclic voltammetry , chemistry , x ray photoelectron spectroscopy , amperometry , glassy carbon , electrode , inorganic chemistry , hydrogen peroxide , electrochemistry , catalysis , analytical chemistry (journal) , chemical engineering , organic chemistry , engineering
As an alternative selection of electrocatalytic surface modifier, the electrochemically generated copper oxides is re‐ investigated by using cyclic voltammetry (CV), scanning electron microscopy (SEM) and X‐ray photoelectron spectroscopy (XPS). Interesting phenomena have been found, which indicate that the electrodeposition from the Cu 2+ solution under cyclic voltammetric conditions can generate a transparent Cu(OH) 2 crystalline on the surface of glassy carbon electrodes, and this crystalline can be further transferred to a novel cubic opaque CuO crystalline of about 300 nm in size by second step of cyclic voltammetry in pH 12 NaOH solution. The final electrode (denoted as nano‐CuO/GCE) can catalyze the oxidation (as well as the reduction) of H 2 O 2 in basic solutions. It shows pH dependent three‐part catalytic mechanism in the range from pH 7 to pH 14. In 0.10 mol/L NaOH solution, the amperometric response at 0.15 V (vs. SCE) can give a current sensitivity as high as 139 mA/(mol·L −1 ) in the rage of 5.0×10 −7 −6.0×10 −4 mol/L with a lower detection limit ( s / n =3) of 2.5×10 −8 mol/L, and a current sensitivity of 78.4 mA/(mol·L −1 ) in the rage of 6.0×10 −4 –2.0×10 −3 mol/L. This electrode also has excellent reproducibility and stability. The mechanisms for the two steps of preparation and the catalytic reactions are proposed. The nano‐CuO crystalline modified electrode may have more applications in the field of electrochemical sensing.