Formation of nanostructured graphitic carbon from coconut waste via low-temperature catalytic graphitisation

Abstract

We report a simple and relatively low-temperature method for producing graphitic carbon from renewable and abundant coconut coir. This study also aims to promote the utilisation and conversion of locally sourced coconut coir waste into value-added materials. We obtained amorphous charcoal by carbonising coconut coir and transforming it into graphitic carbon using a Ni-based catalyst at 1300 °C for 3 h. The HR-TEM, XPS, XRD and Raman spectroscopy results confirmed the structural transformation from amorphous to graphitic nanostructure. The formation of graphitic layers is observed in the form of well-defined lattice fringes that are separated by an interplanar distance of 0.3367 nm around Ni. Graphitic carbon has a high graphitisation degree of 84.88%, which is slightly lower than that of commercial graphite (90.23%). This structural change enhances the electrical conductivity of powder carbon from 14.97 to 25.75 S/cm under 741 kPa of pressure. Producing graphitic and conductive carbon from renewable coconut coir can alleviate the environmental burden of coconut waste.

Keywords

• Coconut coir waste
• Value-added materials
• Catalytic graphitisation
• Graphitic carbon