The study by Keiluweit et al. investigates the dynamic molecular structure of plant biomass-derived black carbon (biochar) formed through incomplete combustion. Using a range of techniques including BET-N2 surface area, X-ray diffraction (XRD), synchrotron-based Near-edge X-ray Absorption Fine Structure (NEXAFS), and Fourier transform infrared (FT-IR) spectroscopy, the researchers examine the physical organization and chemical complexity of biochar from wood and grass materials as the charring temperature increases from 100 to 700°C. The results reveal four distinct categories of biochar: (i) transition chars with preserved crystalline character, (ii) amorphous chars with randomly mixed heat-altered molecules, (iii) composite chars with poorly ordered graphene stacks, and (iv) turbostratic chars dominated by disordered graphitic crystallites. These categories are associated with different environmental persistence and sorptive properties, highlighting the importance of understanding the structural and chemical variations in biochar for its effective use in soil amendments and carbon sequestration.The study by Keiluweit et al. investigates the dynamic molecular structure of plant biomass-derived black carbon (biochar) formed through incomplete combustion. Using a range of techniques including BET-N2 surface area, X-ray diffraction (XRD), synchrotron-based Near-edge X-ray Absorption Fine Structure (NEXAFS), and Fourier transform infrared (FT-IR) spectroscopy, the researchers examine the physical organization and chemical complexity of biochar from wood and grass materials as the charring temperature increases from 100 to 700°C. The results reveal four distinct categories of biochar: (i) transition chars with preserved crystalline character, (ii) amorphous chars with randomly mixed heat-altered molecules, (iii) composite chars with poorly ordered graphene stacks, and (iv) turbostratic chars dominated by disordered graphitic crystallites. These categories are associated with different environmental persistence and sorptive properties, highlighting the importance of understanding the structural and chemical variations in biochar for its effective use in soil amendments and carbon sequestration.