Abstract
The role of the Mo2C/oxide interface on multi-layer graphene (MLG) nucleation during a chemical vapor deposition (CVD) process is investigated. During the CVD process, MLG growth is only observed in the presence of a Mo2C/SiO2 interface, indicating that the chemical reactions occurring at this interface trigger the nucleation of MLG. The chemical reaction pathway is explained in four steps as (1) creation of H radicals, (2) reduction of the oxide surface, (3) formation of C–C bonds at O–H sites, and (4) expansion of graphitic domains on the Mo2C catalyst. Different Mo2C/oxide interfaces are investigated, with varying affinity for reduction in a hydrogen environment. The results demonstrate a catalyst/oxide bifunctionality on MLG nucleation, comprising of CH4 dehydrogenation by Mo2C and initial C–C bond formation at the oxide interface.
Highlights
The role of the Mo2C/oxide interface on multi-layer graphene (MLG) nucleation during a chemical vapor deposition (CVD) process is investigated
We will test this model by performing the CVD process in absence of hydrogen gas, as well as using different oxide ( TiO2, Al2O3, MgO) interfaces, in which we expect a dependence of MLG nucleation on the oxide reducibility
The outcome of this study shows that the catalyst-oxide interface interaction is crucial for understanding the MLG synthesis on Mo2C thin films
Summary
The role of the Mo2C/oxide interface on multi-layer graphene (MLG) nucleation during a chemical vapor deposition (CVD) process is investigated. Mo2C in combination with ZSM-5 zeolite supports causes aromatization of CH4, whereas this is not the case for only Mo2C or ZSM-5 separately[23] This shows that both the catalyst and neighboring oxide can play a role in graphene synthesis, which to our knowledge has not yet been investigated. We will introduce a model for explaining the MLG nucleation by catalyst/ oxide bi-functionality This model is based on the complementary role of MoCx (x = 0–0.5) for CH4 dehydrogenation and SiO2 for C–C bond formation after reduction with hydrogen. We will test this model by performing the CVD process in absence of hydrogen gas, as well as using different oxide ( TiO2, Al2O3, MgO) interfaces, in which we expect a dependence of MLG nucleation on the oxide reducibility. The outcome of this study shows that the catalyst-oxide interface interaction is crucial for understanding the MLG synthesis on Mo2C thin films
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
