The Direct Electrochemical Oxidation of Ammonia in Propylene Carbonate: A Generic Approach to Amperometric Gas Sensors

The direct electrochemical oxidation of ammonia in propylene carbonate is reported for the first time. The voltammetric responses at glassy carbon, boron-doped diamond, edge and basal plane pyrolytic graphite electrodes are explored and compared with the outcome indicating that the optimum electrode substrate for analytical purposes in this solvent is glassy carbon. Proof-of-concept is shown for the amperometric detection of ammonia using basal plane pyrolytic graphite electrodes abrasively modified with glassy carbon spheres. Given the significantly lower vapor pressure of propylene carbonate in comparison to water the implications for extending the life-time of practical sensors are evident. Propylene carbonate shows a wide potential window with glassy carbon electrodes permitting this approach to be used for a potential diversity of gaseous analytes.

[1]  S. Rulyak,et al.  Breath Ammonia Testing for Diagnosis of Hepatic Encephalopathy , 2005, Digestive Diseases and Sciences.

[2]  K. Morokuma,et al.  Sensitivity of ammonia interaction with single-walled carbon nanotube bundles to the presence of defect sites and functionalities. , 2005, Journal of the American Chemical Society.

[3]  A. Berg,et al.  Ammonia sensors and their applications - a review , 2005 .

[4]  Gareth R. Williams,et al.  Graphite powder and multiwalled carbon nanotubes chemically modified with 4-nitrobenzylamine. , 2005, Chemphyschem : a European journal of chemical physics and physical chemistry.

[5]  Richard G Compton,et al.  Electrocatalysis at graphite and carbon nanotube modified electrodes: edge-plane sites and tube ends are the reactive sites. , 2005, Chemical communications.

[6]  A. Bard,et al.  Scanning Electrochemical Microscopy and Conductive Probe Atomic Force Microscopy Studies of Hydrogen-Terminated Boron-Doped Diamond Electrodes with Different Doping Levels , 2004 .

[7]  R. R. Moore,et al.  Investigation of modified basal plane pyrolytic graphite electrodes: definitive evidence for the electrocatalytic properties of the ends of carbon nanotubes. , 2004, Chemical communications.

[8]  N. Lawrence,et al.  Elucidation of the Electrochemical Oxidation Pathway of Ammonia in Dimethylformamide and the Room Temperature Ionic Liquid, 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide , 2004 .

[9]  R. R. Moore,et al.  Basal plane pyrolytic graphite modified electrodes: comparison of carbon nanotubes and graphite powder as electrocatalysts. , 2004, Analytical chemistry.

[10]  Guofang Zhong,et al.  Multi-walled carbon nanotube-based gas sensors for NH3 detection , 2004 .

[11]  Khalifa Aguir,et al.  Development of an ammonia gas sensor , 2003 .

[12]  S. D. Torresi,et al.  A New Sensor for Ammonia Determination Based on Polypyrrole Films Doped with Dodecylbenzenesulfonate (DBSA) Ions , 2002 .

[13]  T. Tsang,et al.  13C n.m.r. study of charge transfer in alkali metal-ammonia graphite compounds , 1987 .

[14]  H. Mishima,et al.  Electrochemical oxidation of ammonia in alkaline solutions : its application to an amperometric sensor , 1998 .

[15]  Yoichi Takahashi,et al.  Absorption of ammonia by stage 1 alkali metal graphite intercalation compounds , 1988 .