Low-potential Amperometric Determination of Hydrogen Peroxide with a Carbon Paste Electrode Modified with Nanostructured Cryptomelane-type Manganese Oxides
Nanostructured cryptomelane-type manganese oxides were synthesized, characterized, and evaluated for chemical sensing. Cryptomelane-type manganese oxides are nanofibrous crystals with sub-nanometer open tunnels that provide a unique property for sensing applications. Carbon paste electrodes (CPEs), modified with the nanostructured cryptomelane-type manganese oxides, were investigated for amperometric detection of hydrogen peroxide. With an operating potential of +0.3 V versus Ag/AgCl, H{sub 2}O{sub 2} produces catalytic oxidation currents at the modified CPE, which can be exploited for quantitative determinations. The amperometric signals are linearly proportional to H{sub 2}O{sub 2} concentration in the range 1.0 x 10{sup -4}-6.9 x 10{sup -4} M with a correlation coefficient of 0.995 (n = 7). At a signal-to-noise ratio of 3, a detection limit of 2 {micro}M can be observed for the carbon paste electrode modified with 5.5 wt% cryptomelane-type manganese oxides. In addition, the sensor has a good stability and reproducibility. The construction and renewal are simple and inexpensive. A possible response mechanism was proposed and discussed. The significant electrocatalytic activity of the modified CPE may result from the nanostructure of cryptomelane-type manganese oxides.
- Research Organization:
- Pacific Northwest National Lab., Richland, WA (US), Environmental Molecular Sciences Laboratory (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 15011274
- Report Number(s):
- PNNL-SA-43689; 6899; TRN: US200506%%28
- Journal Information:
- Electrochemistry Communications, Vol. 7, Issue 2; Other Information: PBD: 1 Feb 2005
- Country of Publication:
- United States
- Language:
- English
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