Chemical Vapor Deposition of N-Doped Graphene through Pre-Implantation of Nitrogen Ions for Long-Term Protection of Copper.

Luoqiao Han,Haiyan Chen,Hong Yan,Lei Dong,Bo Zhang,Shuai Yang,Dejun Li,Ran Guan,Jing Wu,Birong Luo,Aiheng Yuan

doi:10.3390/ma14133751

Abstract

Nitrogen-doped graphene (NG) was synthesized through the chemical vapor deposition (CVD) of graphene on Cu substrates, which were pre-implanted with N ions by the ion implantation method. The pre-implanted N ions in the Cu substrate could dope graphene by the substitution of C atoms during the CVD growth of graphene, forming NG. Based on this, NG’s long-term protection properties for Cu were evaluated by ambient exposure for a corrosion test. The results showed that NG can obviously reduce the natural oxidation of Cu in the long-term exposure compared with the case of pristine graphene (PG) coated on Cu. Moreover, with the increase in pre-implanted N dose, the formed NG’s long-term protection for Cu improved. This indicates that the modification of graphene by N doping is an effective way to improve the corrosion resistance of the PG coating owing to the reduction in its conductivity, which would inhibit galvanic corrosion by cutting off electron transport across the interface in their long-term protection. These findings provide insight into corrosion mechanisms of the graphene coating and correlate with its conductive nature based on heteroatoms doping, which is a potential route for improving the corrosion resistance of graphene as an effective barrier coating for metals.

Highlights

Graphene is a typical two-dimensional (2D) material with a tight hexagonal structure and many kinds of outstanding properties such as high strength, excellent thermal conductivity, and superior impermeability to gases [1,2,3,4]
The N-doped graphene (NG)-coated Cu with a high N dose showed a better corrosion resistance than NG with a low N dose and pristine graphene (PG)-coated Cu for a long-term exposure to air at room temperature. These results demonstrate that the natural oxidation resistance of Cu coated by chemical vapor deposition (CVD)-grown NG is highly dependent on their doped N concentration, providing insights into the corrosion mechanisms and correlations between graphene coatings and graphene-like materials with modified electrical properties
As the concentration of N ions implanted in the Cu foil should be a Gaussian distribution from the surface to a certain depth, the implanted N ions partly segregated and diffused to the surface, and combined with C atoms decomposed from Cu(OAc)2, forming N-doped graphene with the assistance of a Cu catalyst

Summary

Introduction

Graphene is a typical two-dimensional (2D) material with a tight hexagonal structure and many kinds of outstanding properties such as high strength, excellent thermal conductivity, and superior impermeability to gases [1,2,3,4]. The NG-coated Cu with a high N dose showed a better corrosion resistance than NG with a low N dose and PG-coated Cu for a long-term exposure to air at room temperature These results demonstrate that the natural oxidation resistance of Cu coated by CVD-grown NG is highly dependent on their doped N concentration, providing insights into the corrosion mechanisms and correlations between graphene coatings and graphene-like materials with modified electrical properties

Experimental Section

Characterization of PG- and NG-Coated Cu

Results and Discussion

Conclusions