From synthesis to applications: evolution of metal-embedded laser-induced graphene (M-LIG)

Metal-embedded laser-induced graphene (M-LIG) represents a versatile class of hybrid nanostructures that merge the exceptional electrical, thermal, and mechanical properties of laser-induced graphene (LIG) with the catalytic and electronic functions of embedded metal nanoparticles. This feature article reviews the evolution of M-LIG, beginning with the principles and mechanisms of laser-induced graphitization and extending to strategies for in situ or post-metal incorporation into carbon precursors. Drawing on nearly a decade of experience in the field, we discuss how laser parameters, precursor chemistry, and substrate choice influence the oxidation state, morphology, and defect engineering of the resulting M-LIG architectures. Particular emphasis is placed on how metal incorporation modulates the physicochemical properties of LIG, thereby enabling multifunctionality across diverse applications. Key areas critically reviewed include energy storage (supercapacitors and batteries), electrocatalysis (water splitting, CO₂ and N₂ reduction), flexible electronics, and sensors. The synergistic interactions between graphene frameworks and metal centers are analysed to elucidate structure-property relationships. Finally, we highlight current challenges and future opportunities. These include improving scalability in fabrication, advancing compositional tuning for tailored performance, and enhancing integration into functional devices. This review aims to provide a foundational understanding to guide future research and efforts in this rapidly advancing field.