Single-Layer Graphene as an Effective Mediator of the Metal–Support Interaction

Abstract

Single-layer chemical vapor deposition (CVD)-grown graphene was transferred onto a ZnO (0001) substrate forming a large-area, low-defect density, protective layer. The quality of the graphene layer and its effect on the interaction between the ZnO support and vapor-deposited cobalt particles was investigated by spectroscopic and microscopic techniques. We demonstrate that the in-between graphene layer influences both the oxidation state and the morphology of cobalt upon annealing in vacuum. In particular, cobalt strongly interacts with the bare ZnO substrate forming flat particles, which are readily oxidized and redispersed upon annealing in ultrahigh vacuum conditions. In contrast, in the presence of the graphene interlayer, cobalt forms highly dispersed nanoparticles, which are resistant to oxidation, but prone to surface diffusion and agglomeration. The graphene layer exhibits remarkable stability upon cobalt deposition and vacuum annealing, while interaction with reactive gases can facilitate the formation of defects.

Growth morphology and properties of metals on graphene

“…graphene grown on Si-terminated SiC, graphene on SiO 2 , and graphene grown on metals. We should also note limited studies of metal growth on graphene supported on other substrates, e.g., Co deposited on G1/Zn(0 0 0 1) at room temperature and annealed to 350°C [215].…”

Graphene‐Coated ZnO and SiO2 as Supports for CoO Nanoparticles with Enhanced Reducibility

“…The high electronic conductivity of graphene facilitates electron transfer for more effective electrocatalysis, and its optical transparency and high electron mobility make it attractive in photocatalysis. However, despite the various potential advantages, only a few works have studied graphene‐coated oxides as potential supports in catalysis …”

Effects of graphene defect on electronic structures of its interface with organic semiconductor

“…The low intensity of the signal at 1350 cm À1 (D peak) suggests a low defect density in the as-grown graphene sample. 45,46 Upon 30 s of hydrogen plasma treatment (line b), intensity ratio of the D peak to G peak (I D /I G ) increases dramatically from 1/10 to 1/2. This ratio further increases to 2/1 in the sample with 5 min of plasma treatment (line c).…”