Precision Synthesis of Biomass‐Derived Graphene‐Like Carbon With Tailored Crystallinity via Controlled Flash Joule Heating

Establishing correlations between processing parameters, structural characteristics, and application performance are essential for controlled synthesis of biomass‐derived graphene‐like carbon via flash Joule heating (FJH). Herein, we developed a controlled dual‐phase synthesis strategy in which pre‐pyrolysis stabilizes the carbon framework and programmable FJH subsequently tailors the carbon architecture for different application scenarios. By decoupling the thermodynamic driver (current) from kinetic relaxation (duration), a processing structure phase‐map framework was established to capture and guide the continuous transition from defect‐rich amorphous carbon to highly ordered turbostratic nanographite (TNG). This strategy reduces the reliance on empirical trial‐and‐error. As a demonstrative application for the high‐graphitization regime, targeted TNG exhibited a peak electrical conductivity of 59.06 S cm −1 . Incorporating 1.2 wt.% TNG into epoxy resin increased the flexural modulus by 2.8‐fold and enhanced thermal conductivity, demonstrating the link between programmed structural evolution and macroscopic performance. This strategy offers a route for converting heterogeneous waste biomass into structurally tunable carbon materials.