Direct conversion of CO₂ to graphene via vapor–liquid reaction for magnesium matrix composites with structural and functional properties

Converting CO₂ to valuable materials is attractive in environmental protection and resource utilization. In this study, a vapor–liquid interface reaction system for mass production of high-quality graphene is reported. The graphene obtained has high crystallinity and few defects during the reaction of CO₂ and Mg melt. The growth mechanism of graphene is demonstrated in vapor–liquid interface area by combining the CO₂ bubbles as a soft template to guide growth with the confinement effect of dense MgO nanoparticles. The quality of the graphene is verified by epoxy composites with high electromagnetic shielding effectiveness. Additionally, the V–L reaction method ingeniously solves the dispersion of graphene in metal, providing a preparation strategy of Mg matrix composites with structure and function integration.