A Versatile Single-Step Micro- to Nanoparticles Laser Graphitization-Driven Conversion Route for Graphene-Embedded Nanoparticle Composites.

Traditional top-down nanoparticle synthesis is often limited by the high energy demands and costs of mechanical milling and high-power pulsed lasers. Beyond synthesis, integrating these powders into functional devices remains a significant challenge, typically requiring cumbersome, multistep procedures to incorporate particles into conductive support matrices. Building on the established foundation of laser-induced graphene (LIG) synthesis, we introduce a versatile single-step methodology utilizing low-power continuous laser irradiation of phenolic resin blended with microparticle precursors (e.g., Si, SiO, and Mg) to produce functional nanocomposites under ambient conditions. We propose that ultrafast laser-induced photothermal graphitization drives an explosive boiling mechanism, where rapid localized heating converts microparticles into nanoparticles. These ejected molten nanoparticles are simultaneously embedded within the as-formed porous LIG scaffold. Validated across diverse precursors, this versatile process results in a monolithic, self-supporting composite with strong interfacial coupling achieved without binders or postprocessing. Notably, a "laser-milled" SiO/LIG anode synthesized from microprecursors demonstrated performance comparable to analogous anodes fabricated using premade nanoparticles, yielding a lithium-ion battery with a reversible capacity exceeding 1400 mAh/g over 105 cycles at C/7 and 79% retention over 350 cycles at 1.28C. This scalable strategy represents the first investigation into converting raw micropowders and commercial polymers into functional nanoparticle-graphene composites in a single, streamlined step.