The electrochemical behavior and the reversible hydrogen storage capacity of multiwalled carbon nanotubes (MWNTs) have been investigated both in alkaline (6 M KOH) and acid (0.3 M H2SO4) electrolytic solutions by cyclic voltammetry and constant current charge/discharge measurements. Different purification treatments were performed on as-prepared MWNTs to improve hydrogen uptake. About 0.1 wt % of hydrogen was reversibly stored in MWNTs after nitric acid treatment. Vacuum annealing (950°C, 1 h) of MWNTs lowered the electrochemical hydrogen uptake. Finally, electrochemical oxidation of MWNTs at high potentials allowed an increase in hydrogen charge capacity to 0.3 wt %.
Electrochemical characterization of carbon nanotubes for hydrogen storage
BESTETTI, MASSIMILIANO;CAVALLOTTI, PIETRO LUIGI;DUCATI, UMBERTO;LOMBARDI, ILARIA;MAZZOCCHIA, CARLO VITTORIO
2004-01-01
Abstract
The electrochemical behavior and the reversible hydrogen storage capacity of multiwalled carbon nanotubes (MWNTs) have been investigated both in alkaline (6 M KOH) and acid (0.3 M H2SO4) electrolytic solutions by cyclic voltammetry and constant current charge/discharge measurements. Different purification treatments were performed on as-prepared MWNTs to improve hydrogen uptake. About 0.1 wt % of hydrogen was reversibly stored in MWNTs after nitric acid treatment. Vacuum annealing (950°C, 1 h) of MWNTs lowered the electrochemical hydrogen uptake. Finally, electrochemical oxidation of MWNTs at high potentials allowed an increase in hydrogen charge capacity to 0.3 wt %.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
