Conversion of residue biomass into value added carbon materials: utilisation of sugarcane bagasse and ionic liquids

Presented herein is the nitrogen-doped multiwalled carbon nanotubes (N-MWCNTs) production from a residue, sugarcane bagasse, using 1-butyl-3-methylimidazolium chloride [C₄MIM]Cl as the solvent and nitrogen source, and ferrocene as the catalyst source. N-MWCNTs were synthesised using the floating catalyst chemical vapour deposition method at 850 °C. The synthesised N-MWCNTs were characterised using transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), X-ray diffraction (XRD) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy. Hollow tubular structures of N-MWCNTs were observed using TEM. These observations correlated morphology from SEM which showed spaghetti-like structures, and also EDS detected the presence of nitrogen. Raman spectroscopy indicated MWCNT bands, around 1350 and 1580 cm⁻¹ assigned to D-band and G-band due to defective and graphitic carbon vibrations, respectively. Also, XRD patterns showed typical N-MWCNT structures with a strong intensity peak at 2θ = 26.4° which was indexed as the C₍₀₀₂₎ reflection of graphite. TGA showed an N-CNTs thermogram curve, with the main decomposition temperature around 590 °C. The study showed that N-MWCNTs were successfully synthesised from sugarcane bagasse. The study significantly establishes a strategy for utilisation and value addition of a residue which is abundant from sugar production mills.