Journal
NEW CARBON MATERIALS
Volume 26, Issue 3, Pages 224-228Publisher
ELSEVIER
DOI: 10.1016/S1872-5805(11)60078-4
Keywords
Carbon nanotubes; Carbonyl; Carboxyl; Hydroxyl; Pseudo-capacitance
Categories
Funding
- National Science Foundation of China [50328204, 50472084, 50632040]
- Natural Science Foundation of Liaoning Province of China [20061078]
- Foundation of Liaoning Education Committee of China [L2010197]
Ask authors/readers for more resources
Concentrated H2SO4:HNO3 mixed acids, air, nitric acid and potassium permanganate were used to oxidize carbon nanotubes (CNTs) to introduce surface functional groups (SFGs) and the effects of the type and amount of SFGs on the electrochemical properties of CNT supercapacitors were investigated. XPS analysis shows that the mixed acid oxidation produces carbonyl (C=O) and the carboxyl (O-C=O) groups, the air oxidation results in hydroxyl and the smallest amount of carbonyl and carboxyl groups, and both the nitric acid and potassium permanganate treatments result in a moderate amount of carbonyl and carboxyl groups. It was found that the specific surface area and pore structures of the four samples are similar and carbonyl and carboxyl groups contribute the most to pseudo-capacitance through a Faradic reaction. In particular, the carbonyl group has a proportional relationship to the capacitance of CNTs. However, the hydroxyl group does not lead to an obvious increase of pseudo-capacitance, but can increase the electric double layer capacitance. The carbonyl and the carboxyl groups are advantageous for fast Faradic reactions to introduce pseudo-capacitance, owing to their lower charge transfer resistance than that of the hydroxyl group.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available