Synthesis of Turbostratic Graphene Derived from Biomass Waste Using Long Pulse Joule Heating Technique

This study addresses the challenge of the scalable, cost-effective synthesis of high-quality turbostratic graphene from low-cost carbon sources, including biomass waste such as sugarcane leaves, bagasse, corncobs, and palm bunches, using the Direct Current Long Pulse Joule Heating (DC-LPJH) technique. By optimizing the carbonization process and blending biomass-derived carbon with carbon black and turbostratic graphene, the gram-scale production of turbostratic graphene was achieved in just a few seconds. The synthesis process involved applying an 18 kJ electrical energy pulse for 1.5 s, resulting in temperatures of approximately 3000 K that facilitated the transformation of the carbon atoms into well-ordered turbostratic graphene. Structural and morphological characterization via Raman spectroscopy revealed low-intensity or absent D bands, with a high I-2D/I-G ratio (similar to 0.8-1.2), indicating monolayer turbostratic graphene formation. X-ray photoelectron spectroscopy (XPS) identified sp(2)-hybridized carbon and oxygenated functional groups, while NEXAFS spectroscopy confirmed the presence of graphitic features and both sp(2) and sp(3) bonding states. Energy consumption calculations for the DC-LPJH process demonstrated approximately 10 kJ per gram, demonstrating the potential for cost-effective production. This work presents an efficient approach for producing high-quality turbostratic graphene from low-cost carbon sources, with applications in enhancing the properties of composites, polymers, and building materials.