Understanding oxidative reaction of carbon nanoplatelets towards tailored physicochemical properties

Abstract

The oxidation and exfoliation of graphitic carbon sheet-like materials has been studied in various works but in-depth understanding of reagent roles still need more focused studies since it depends on specific carbon starting materials. This study investigated reaction time, KMnO4 and NaNO3 weight ratio effect to carbon nanoplatelets (CNPs) oxidation. The oxygen-containing moieties were tailored by the KMnO4: CNP mass ratio and the highest ratio of 12:1 had the lowest carbon/oxygen ratio of 0.78 (from 5.63 of pristine CNP). The carboxylic acid content was raised by ten-fold from that of pristine CNP when the KMnO4: CNP mass ratio was increased to 9:1. The study also established that about 50% of the total oxygen-containing groups were located on CNP sheet surfaces. The KMnO4 and H2SO4/H3PO4 reagent synergy in the current method reduced the lattice sizes of CNP from 15 nm to 9 nm. Also, at a constant KMnO4: CNP mass ratio of 6:1, NaNO3: CNP mass ratio of 1:2, 1:1 and 2:1 culminated in further CNPs tearing effect to 7, 5 and 4 nm, respectively. Reaction conditions and reagent weight ratio are dynamic in controlling physicochemical characteristics of carbon materials and it is mostly impractical to tune one aspect without necessarily influencing others.