Preparation and characterisation of carbonaceous products with three-dimensional grape-bunch structure via self-assembling of saccharides and hydroxylated multi-wall carbon nanotubes through hydrothermal method

Abstract

A series of carbon-rich products with three-dimensional (3D) grape-bunch structure have been synthesised by the hydrothermal carbonisation of saccharides (glucose, sucrose and starch) with the assistance of hydroxylated multi-wall carbon nanotubes (MWCNTs). The carbonaceous spheres are regarded as ‘grapes’; the hydroxylated MWCNTs were used as connected carbon wires that could be embedded into the ‘grapes’ via self-assembling of hydrophilic groups to form a 3D-grape-bunch structure. The carbonaceous products are characterised by scanning electron microscopy, Brunauer–Emmett–Teller, Fourier transform infrared, X-ray diffraction, Raman spectroscopy and thermogravimetry–differential scanning calorimetry. The results show that the ‘grapes’ (carbonaceous spheres) have average diameters of 0·1–3 μm (depending on the type of saccharides), which were connected by the hydroxylated MWCNTs to form the 3D-grape-bunch structure. The 3D-grape-bunch structure containing many aromatic and reactive oxygen functional groups has relatively high special surface area, a low disordered/graphitic ratio and potential applications in many fields.