Characterization of functional groups on oxidized multi-wall carbon nanotubes by potentiometric titration

•We apply principle component analysis on the potentiometric titration of functionalized MWCNT.•We found there are 5 major Brønsted acidity functional groups on the surface of MWCNT.•This titration method can potentially be an easy, fast routine characterization method for carbon material.

Since the discovery of carbon nanotubes (CNT), this material has been recognized as an attractive material because of its exceptional physical and chemical properties. CNT must be functionalized for most applications. However, the functional groups on the CNT are very complex. Here a simple acid–base titration is introduced to characterize the functionalized multi-wall carbon nanotubes (MWCNT). By using the principle component analysis (PCA) of a titration data set of 21 independent curves, we can calculate the density of Brønsted acid functional groups for each differently functionalized MWCNT.

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