from the conferences organized by TANGER Ltd.
Sodium dodecyl sulfate (SDS), sodium laureth sulfate (SLES), cocamidopropyl betaine (CAPB) and polyvinylpyrrolidone (PVP) have been chosen as dispersants in preparation of stable water suspensions of carbon nanotubes (CNTs). BET specific surface areas of buckypapers obtained by vacuum filtration of the suspensions are approximately 80 m2/g and do not differ significantly from each other. Sheet resistance of backypapers obtained from the anionic and amphoteric surfactants (SDS, SLES and CAPB) were also close to each other and is in the range 0.5-0.6 /sq. Only the use of PVP (polymeric dispersing agent) resulted in signifficant decrease of sheet resistance by two orders of magnitude. The heterogeneous electron transfer (HET) rate constant for hexacyanoferrate(III)/(II) and hexaamminoruthenium(III)/(II) redox couples was higher by one and more orders of magnitude on CNT electrodes treated with dispersants with respect to pristine CNTs. Adsorbed SDS, CAPB and PVP contributed to the slight lowering of onset potential of oxygen reduction reaction (ORR). From the point of view of ORR catalysis, the most promising dispersant agent is PVP. The CNT/PVP electrode showed the highest ORR limiting current and number of electron transfers close to four.
Keywords: Carbon nanotubes, dispersant agents, heterogeneous electron transfer, oxygen reduction reaction© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.