Eco-friendly synthesis and characterization of high quality reduced graphene oxide from dry coconut shells

This work presents eco-friendly synthesis of high quality reduced graphene oxide (rGO) from dry coconut shells through pyrolysis carbonization technique by heating at high temperatures (at 400 °C and 600 °C). The resulting material has been thoroughly characterized, revealing optical and electrical properties. The synthesized rGO demonstrates a significant specific surface area of 356.9783 m²/g, featuring a small pore size division between 1.85 to 86.71 nm, with an average pore size of 31.76 Å. The material’s properties like gas adsorption and semiconductor behavior are confirmed through various analytical techniques, including BET analysis, XRD, Raman spectroscopy, XPS, HRTEM, FTIR, and UV–Vis NIR spectroscopy. The UV–Vis NIR spectroscopy results show the optical energy band gap decreasing from 1.95 to 1.53 eV with rising temperature (400 °C to 600 °C), correlating with an increase in electrical conductivity from 289 to 400 $\mu$S/cm higher than the reported values in contemporary literatures. The heating at high temperature (600 °C) is found to yield the highest specific surface area and electrical conductivity. These findings demonstrate the successful synthesis of high-performance rGO from coconut shells, offering promising applications in various fields including Gas sensing, Biosensing, Optoelectronics and Semiconductor technology.