Electrochemistry of Carbon Nanotubes: Reactive Processes, Dual Sensing-Actuating Properties and Devices

• Published in: Chemphyschem 2012-06, Vol.13 (8), p.2108-2114
• Main Authors: Martínez, José G., Sugino, Takushi, Asaka, Kinji, Otero, Toribio F.
• Format: Article
• Language: English
• Subjects: carbon; Chemistry; Electrochemical Techniques; Electrochemistry; Electrolytes - chemistry; Exact sciences and technology; General and physical chemistry; Kinetics; nanotubes; Nanotubes, Carbon - chemistry; Oxidation-Reduction; Polymers - chemistry; Polyvinyls - chemistry; sensors; Temperature
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201100931

Single‐walled carbon nanotubes (SWCNT) embedded in a non‐electroactive polymer are electrochemically characterized. The increasing voltammetric maximums obtained with rising temperature or electrolyte concentration point to a chemical nature of the processes. The chemical kinetic control of the processes is corroborated by its empirical chemical kinetics: the initial reaction rates are obtained from the chronoamperometric responses to potential steps. The activation energy of the reaction includes information about the structural state of the SWCNT before the potential step. Under constant current the potential evolution (chronopotentiometric response) and consumed electrical energy at any time change as a function of (are sensors of) the experimental temperature or the electrolyte concentration. The reactive material, or any device based on this material, senses these working variables, and shows dual and simultaneous actuating–sensing properties. Electrochemical responses from carbon nanotubes (CNT) as a function of different variables are presented and discussed. The results fit those expected from chemical reactions and cannot be explained in terms of a capacitive origin (see picture). The reactive material senses the working conditions and thus shows dual sensing–actuating behaviour.