Growth of Uniform Monolayer Graphene Using Iron-Group Metals via the Formation of an Antiperovskite Layer

Abstract

It has been generally accepted that iron-group metals (iron, cobalt, nickel) consistently show the highest catalytic activity for the growth of carbon nanomaterials, including carbon nanotubes (CNTs) and graphene. However, it still remains a challenge for them to obtain uniform graphene, because of their high carbon solubility, which can be attributed to an uncontrollable precipitation in cooling process. The quality and uniformity of the graphene grown on low-cost iron-group metals determine whether graphene can be put into the mass productions or not. Here, we develop a novel strategy to form an antiperovskite layer using ambient-pressure chemical vapor deposition (APCVD), which, so far, is the only known way for iron-group metals to prepare uniform monolayer graphene with 100% surface coverage. Our strategy utilizes liquid metal (e.g., gallium) to assist iron-group metals to form an antiperovskite layer that is chemically stable throughout the high-temperature growth process and then to seal the passageway of carbon segregation from the metal bulk during cooling. With the advantage of forming antiperovskite structure, the uniform monolayer graphene can always be obtained under the variations of experimental conditions. Our strategy solves the problem about how to get uniform graphene film on high-solubility carbon substrate, to utilize the high catalytic activity of low-cost iron-group metals and to realize low-temperature growth by chemical vapor deposition.

Partially Graphitized Iron−Carbon Hybrid Composite as an Electrochemical Supercapacitor Material

“…At higher temperatures, the Fe 3+ ions convert to Fe 3 O 4 or Fe by carbon reduction and simultaneously carbon diffuses into the iron oxide particles. The temperature dependency leads to the carbon segregation from the bulk during cooling and catalyzed the growth of graphitized structure and iron carbide (Figure b) . The graphitized structures along the particles are defected having an interlayer spacing of 4 Å (marked with a red arrow, Figure c).…”

Partially Graphitized Iron-Carbon Hybrid Composite as Electrochemical Supercapacitor Material

“…The temperature dependency leads to the carbon segregation from the bulk during cooling and catalyzed the growth of graphitized structure and iron carbide. [26][27][28][29][30] The possible mechanism for graphitization is shown in Figure 1b.…”

Precise Vapor-Phase Synthesis of Two-Dimensional Atomic Single Crystals

“…To grow monolayer graphene single crystals, it is necessary to efficiently suppress the carbon precipitation and prevent the inhomogeneous crystal growth via rationally designing growth substrates (Dai et al., 2011, Chen et al., 2015, Wang et al., 2013). The carbon solubility in the substrate influences the dissolution of active species (Wu et al., 2014).…”