Quantitative Measurement of Functional Groups on Nanocarbon Allotropes Surface by Boehm Titration

Abstract

Various nanocarbons (NCs) were used to study their surface groups under standardized Bohem titration, including: multiwalled carbon nanotube (CNT), graphene (G), Vulcan carbon (VC), and nanodiamond (ND). Endpoint-measured titration using second derivative method to quantify carboxylic, lactonic, and phenolic groups created on treated carbon surfaces shows a high precision comparable to other recent reports and with errors of 1 order of magnitude lower. The results exhibit major concentration of carboxyl group increased after the NCs were oxidized compared to the amount of other functional groups like phenols and lactonic groups. It is important highlight, the concentration ratio of carboxyl group with VC:VC-O was showed at 1:77, exhibited a major result regarding other NCs which exhibited ratios of 1:4.5, 1:1.4, and 1:2.5 for ND:ND-O, CNT:CNT-O, and G:G-O, respectively. It is concluded that VC is a NC that competes and excels in its capacity of oxidation with respect to the popular NCs as CNT, graphene (G), and ND.