The Effect of Functional Groups on the Electrocatalytic Activity of Carbon Nanotubes with Different Wall Numbers toward Carbohydrazide Oxidation Reaction.

Carbohydrazide could be applied as fuels for fuel cells to avoid the toxicity of hydrazine. Carbon nanotubes (CNTs) exhibit an improved electrocatalytic activity toward carbohydrazide oxidation reaction than other carbon materials like carbon black or multi-layer graphene, however, the role of defects and functional groups of CNTs for the reaction is not clear. In this study, the electrocatalytic properties of CNTs toward the carbohydrazide oxidation reaction is investigated, which demonstrate that the content of carboxyl groups is crucial to the catalytic activity. The one with higher carboxyl groups exhibits an improved catalytic activity toward carbohydrazide oxidation reaction. Furthermore, density functional theory calculation reveals that the carboxyl groups could increase the adsorption of carbohydrazide molecules on CNTs, which benefits their catalytic activity.