LAUSR

Graphitic 1D and hybrid nanomaterials represent a powerful solution in composite and electronic applications due to exceptional properties, but large‐scale synthesis of hybrid materials has yet to be realized. Here, a rapid, scalable method to produce graphitic 1D materials from polymers using flash Joule heating (FJH) is reported. This avoids lengthy chemical vapor deposition and uses no solvent or water. The flash 1D materials (F1DM), synthesized using a variety of earth‐abundant catalysts, have controllable diameters and morphologies by parameter tuning. Furthermore, the process can be modified to form hybrid materials, with F1DM bonded to turbostratic graphene. In nanocomposites, F1DM outperform commercially available carbon nanotubes. Compared to current 1D material synthetic strategies using life cycle assessment, FJH synthesis represents an 86–92% decrease in cumulative energy demand and 92–94% decrease in global‐warming potential. This work suggests that FJH affords a cost‐effective and sustainable route to upcycle waste plastic into valuable 1D and hybrid nanomaterials.