Transforming biomass to graphitic carbon: Catalytic mechanisms, structural refinement, and emerging applications

Conventional graphite production strategies-both the extraction of natural graphite and graphitization of fossil-derived carbon at temperatures of ∼3000 °C- are highly energy-intensive and contribute to environmental burden. Therefore, graphite production via decarbonization strategies is gaining traction as a means of reducing waste and supporting circular economy principles. Biomass-derived carbon exhibits amorphous or turbostratic nature based on its precursors. Through graphitization at temperatures of 2500 °C-3000 °C, its amorphous structure can be converted into highly ordered graphitic layers. Structural refinement of biomass-derived graphitic carbon can be achieved using suitable catalysts (transition metals including Fe, Ni, and Co) and optimizing processing parameters such as temperature, time, and heating methods. Structural changes achieved through graphitization enhance the functionality of biomass-derived graphitic carbon, rendering it suitable for advanced applications such as energy storage (lithium-ion and sodium-ion batteries and supercapacitors), electrocatalysis (ORR, HER, and OER), electromagnetic interference shielding, and environmental remediation. In this review, we examine various methods used for achieving catalytic graphitization and the effect of different processing parameters on the structural evolution from biomass to graphitic carbon. Additionally, this review investigates the mechanism underlying graphitization and trade-off between porosity and surface area. Furthermore, the utilization of biomass-derived graphitic carbon in battery, supercapacitor, electrocatalysis, and electromagnetic interference shielding applications and challenges associated with structural refinement, scalability, and stability are discussed.