Preparation and characterization of nanocarbons from <em>Nicotiana tabacum</em> stems

Abstract

Nanocarbon materials can improve adsoption capacity if the nano size range is optimized during production. In this study, nanocarbons were prepared from green recyclable waste N. tabacum stem using carbonization process and KOH as the activating agent, thus potentially unclocking value in the otherwise waste material. The formation of nanocarbons was investigated at different KOH concentration, activation temperature and carbonization time. Fourier Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Brunauer–Emmett–Teller (BET) techniques were used to characterise the nanocarbon material. The results showed that nanocarbons with high specific surface areas in excess of 950 m2/g and nanostructured morphologies characterized by pore width averages ranging from 3.33–8.87 nm, pore diameter 10.59–45.30 nm and particle size 25.34–54.88 nm could be formed. Optimum nanocarbon production was achieved when the precursor was activated using 10% KOH and carbonized at a temperature of 400 ℃ for 4 h. Characteristic FT-IR absorption bands were observed in all carbonized samples. SEM images revealed a dense irregular material with cavities and protuberances. XRD patterns showed that crystallinity of the nanocarbons decreased with increase in carbonization time. The properties reported for the nanocarbons are ideal for adsoption of analytes from complex matrices, hence presenting N. tabacum as a promising low-cost and green alternative precursor for nanocarbon production targeting analytical fields such as solid-phase extraction and solid phase microextraction. The produced nanocarbons appear to be carbon nanoparticles comprising nearly spherical particles.

Keywords

• nanocarbons| <i>Nicotiana tabacum</i>| carbonization time| surface morphology| green technology