Optical properties and defect states of rGO-like carbon derived from biomass with heating treatment

Carbon compounds based on natural materials continue to be studied and developed to produce graphene compounds that are effective and suitable for specific applications. This study reports the effect of heating (400, 600, 800, and 1000 °C) on the optical properties and defects of rGO-like carbon derived from the biomass of coconut shells. The results showed that the heating process on rGO-like causes the loss of functional groups containing oxygen, thereby increasing the C[dbnd]C (sp²) bond, a form of the deformed state. In this study, with the increase of the temperature from 400 to 1000 °C, the more defects with the peak of optical absorption shift from about 245 to 256 nm; in addition, the energy gap decreases from 2.31 to 1.87 eV, the exciton binding energy decreases, and the electrical conductivity increases from 213 to 564 μS/cm. Results indicate that the optical properties of rGO-like carbon from biomass with heating treatment are similar to rGO but cheaper and more environmentally friendly. In the future, it can be recommended as an alternative to replacing commercial/non-biomass rGO in optoelectronic applications.