Low-Temperature Chemical Vapor Deposition of 2D Materials via Single-Atom Catalysis on Liquid Bimetallic Substrates: A Case Study of Graphene Synthesis on Liquid Tin Alloys

Current synthesis and transfer methods of 2D materials (2DMs) have fallen short of realizing their promised high-end applications on an industrial scale. In addressing this gap, the method of chemical vapor deposition (CVD) on a liquid substrate envisions cost-effective continuous synthesis and transfer of single-crystal 2DMs. For practical and economical reasons, unlocking effective low-temperature 2DM growth on a liquid catalyst would be a major milestone. Here, we explore the potential of heterogeneous liquid-phase single-atom catalysts (LSACs) for low-temperature 2DM synthesis, specifically the CVD of graphene on liquid Sn-M alloys (M representing a solute metal, acting as LSACs). Through systematic screening over the periodic table based on physical properties and quantum chemical calculations, we identified liquid Sn-Ni (92:8 atom %) as a promising candidate. Experimental studies in the 1000-1200 K temperature range have revealed clear evidence of catalytic activity by the solute Ni single atoms in the liquid alloy for graphene synthesis. These results indicate the scientific richness and technological opportunities that LSACs can provide for efficient mass production of 2DMs.