Faradaic and Capacitive Components of the CNT Electrochemical Responses

Abstract

The nature of the electrochemical responses from carbon nanotubes (CNTs), capacitive (physical), or Faradaic (chemical, also named p-doping or n-doping) remain controversial. In this chapter, the literature is reviewed and discussed trying to elucidate if some of the two processes prevails, how the presence of chemical reactions can be elucidated and which properties, specific from the chemical processes, can be exploited. Different electrochemical responses and theories trying to explain those responses are discussed. The separation and quantification methodologies of the capacitive and Faradaic components involved in some electrochemical responses from CNTs are presented.

The Energy Consumed by Electrochemical Molecular Machines as Self‐Sensor of the Reaction Conditions: Origin of Sensing Nervous Pulses and Asymmetry in Biological Functions

“…Fortunately, during the last decades some artificial materials mimicking the reactive dense gel from functional cells have arisen. The reversible electrochemical reactions of films (on metals or self‐supported) of conducting polymers, carbon nanotubes, graphenes, and other electroactive materials in aqueous electrolytes, drive conformational movements of the polymeric chains or carbonaceous structures (electrochemical molecular motors) in the film and the reversible exchange of ions and solvent with the electrolyte: the film becomes a dense gel constituted by molecular machines, ions and water …”

“…The reversible electrochemical reactions of films (on metals or self-supported) of conducting polymers, carbon nanotubes, graphenes, and other electroactive materials in aqueous electrolytes, drive conformational movements of the polymeric chains or carbonaceous structures (electrochemical molecular motors) in the film and the reversible exchange of ions and solvent with the electrolyte: the film becomes a dense gel constituted by molecular machines, ions and water. [16][17][18][19][20][21][22][23][24][25][26][27][28][29] The oxidation/reduction (p-doping/p-dedoping) reactions of conducting polymer films has been extensively reviewed during the last years. [30][31][32][33][34][35] When they drive the exchange of anions with the electrolyte the reactions [Eq.…”

Structural and Conformational Chemistry from Electrochemical Molecular Machines. Replicating Biological Functions. A Review

“…Films constituted by large carbon nanotubes also present oxidation structural chronoamperometric responses ,,. Graphene films absorbed on fibroin meshes, show structural voltammetric and chronoamperometric responses.…”

“…Those unusual electrochemical responses were attributed to structural memory effects, relaxation processes,,, hysteresis effects,, or first cycle effect,, being considered as “anomalous” electrochemical responses ,,,. Similar singular electrochemical responses were also attained from carbon nanotubes, graphenes, or bipyridyl bilayers . Consequently only a few research groups have been interested on the theoretical description of those anomalous responses.…”

Niobium Alloying of Self‐Organized TiO2 Nanotubes as an Anode for Lithium‐Ion Microbatteries

“…Energy storage systems delivering high power density and energy density available in large‐scale supercapacitors and Li‐ion batteries have been extensively studied to achieve the market requirements . However, modern microelectronic devices such as backup power for computer memories, MicroElectroMechanical Systems, medical implants, smart cards, radio‐frequency identification tags, and remote sensors have necessitated the development of high performance power sources at the microscale .…”