Sustainable Synthesis and Structural Characterization of Carbon, Graphite, Graphene Oxide, and Reduced Graphene Oxide Derived from Coconut Shells

This study explores the sustainable synthesis and structural characterization of carbon, graphite, graphene oxide (GO), and reduced graphene oxide (rGO) derived from coconut shells. The objective is to investigate the potential of biomass-based precursors to produce functional carbon materials through controlled chemical treatments. X-ray diffraction patterns of carbon and graphite exhibit broad peaks, indicating low crystallinity and amorphous characteristics, while GO and rGO show dominant peaks at 22° and 23°, corresponding to the (002) plane. Scanning electron microscopy confirms the disordered morphology of carbon and graphite, while high-resolution transmission electron microscopy reveals wrinkled GO sheets and partially restacked rGO layers. Fourier transform infrared spectra identify O−H stretching at ~3442 cm−1 in carbon and C=C stretching at 1630 cm−1 in graphite, along with various oxygen-containing functional groups in GO and rGO. Raman spectroscopy shows a sharp G band at 1580 cm−1 in graphite (ID/IG = 0.840), increased disorder in GO (ID/IG = 0.843), and partial graphitic restoration in rGO (ID/IG = 0.841). These findings confirm the successful transformation of coconut shells into valuable carbon-based materials and highlight their potential for use in sustainable energy and electronic applications.