Universal light-induced solid-state single-step approach for the in-situ synthesis of porous graphene-embedded nanoparticles

Metal nanoparticle-carbon (MNP-C) composites, which combine metal nanoparticles with conductive carbon materials like graphene, hold significant potential in medicine, electronics, energy, and environmental applications. However, conventional synthesis methods are often energy-intensive, multi-step, and complex, limiting scalability. In response, this study conducts an in-depth investigation into a versatile, one-step, additive-free laser synthesis method to create self-standing, three-dimensional porous graphene embedded with in-situ formed, tunable MNPs under ambient conditions. By blending laser-induced graphene (LIG) polymer precursors—such as phenolic resins—with various metal salt precursors, including transition, semi-metal, noble, alkali, and alkali earth metals, the method employs rapid, low-power laser irradiation to induce localized pyrolysis. This process simultaneously forms the LIG matrix and embedded nanoparticles, which are either metallic or metal oxides correlating to the reduction potential of the parent metal center. By self-generating a localized carbothermal reducing environment, the investigated method can eliminate the need for additional reducing agents or controlled atmospheres at certain reduction potentials. Moreover, tuning the size and dispersity of the strongly embedded MNPs is displayed by adjusting salt concentrations and lasing parameters. The presented “toolbox" provides a universal and efficient blueprint for producing tunable MNPs embedded within functionalized porous graphene matrices. Additionally, we explore the electrocatalytic properties of these composites for water-splitting applications (>1000 h at ∼300 mV overpotential), demonstrating their high potential in energy conversion technologies.