Limits...
Growth kinetics of white graphene (h-BN) on a planarised Ni foil surface.

Cho H, Park S, Won DI, Kang SO, Pyo SS, Kim DI, Kim SM, Kim HC, Kim MJ - Sci Rep (2015)

Bottom Line: The morphology of the surface and the grain orientation of metal catalysts have been considered to be two important factors for the growth of white graphene (h-BN) by chemical vapour deposition (CVD).Atmospheric annealing with hydrogen reduced the nucleation sites of h-BN, which induced a large crystal size mainly grown from the grain boundary with few other nucleation sites in the Ni foil.A higher growth rate was observed from the Ni grains that had the {110} or {100} orientation due to their higher surface energy.

View Article: PubMed Central - PubMed

Affiliation: 1] Soft Innovative Materials Research Center, Korea Institute of Science and Technology, Chudong-ro 92, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905, Republic of Korea [2] Department of Organic Materials and Fiber Engineering, Chonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 561-756, Republic of Korea.

ABSTRACT
The morphology of the surface and the grain orientation of metal catalysts have been considered to be two important factors for the growth of white graphene (h-BN) by chemical vapour deposition (CVD). We report a correlation between the growth rate of h-BN and the orientation of the nickel grains. The surface of the nickel (Ni) foil was first polished by electrochemical polishing (ECP) and subsequently annealed in hydrogen at atmospheric pressure to suppress the effect of the surface morphology. Atmospheric annealing with hydrogen reduced the nucleation sites of h-BN, which induced a large crystal size mainly grown from the grain boundary with few other nucleation sites in the Ni foil. A higher growth rate was observed from the Ni grains that had the {110} or {100} orientation due to their higher surface energy.

No MeSH data available.


Time evolution of h-BN growth morphology on the Ni foils with ECP/LPH2 and ECP/APH2:(a,e) are SEM images of as annealed sample. (b,f), (c,g), and (d,h) are SEM images of h-BN growth for 1 min, 10 min, and 30 min respectively. The first row and the second row are the Ni foil with ECP/LPH2 and ECP/APH2, respectively. (A) and (B) are magnified SEM images taken from the area of Figure (b) and Figure (f) respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4496663&req=5

f3: Time evolution of h-BN growth morphology on the Ni foils with ECP/LPH2 and ECP/APH2:(a,e) are SEM images of as annealed sample. (b,f), (c,g), and (d,h) are SEM images of h-BN growth for 1 min, 10 min, and 30 min respectively. The first row and the second row are the Ni foil with ECP/LPH2 and ECP/APH2, respectively. (A) and (B) are magnified SEM images taken from the area of Figure (b) and Figure (f) respectively.

Mentions: We assumed that the growth feature of h-BN would be affected by the surface roughness of the Ni foil, similar to graphene growth37. The Ni foils went through either ECP/LPH2 or ECP/APH2 before the growth procedure in order to understand how the surface morphology of the Ni surface affects h-BN growth. Dramatic contrast in the h-BN growth kinetics was found, as shown in Figs 3 and 4. While dense triangular domains were observed on the Ni foil with ECP/LPH2 (Fig. 4(a,b)), large area and continuous domains were observed on the Ni foil with ECP/APH2 (Fig. 4(c,d)). Due to the higher surface roughness, small size h-BN domains were formed from the numerous nucleation sites, and thus, distinctive kinetics depending on the crystalline orientation of Ni were not observed in ECP/LPH2 condition. In the case of ECP/APH2, nucleation sites were limited to the grain boundary with scarce nucleation on the surface of the grains, such that the growth kinetics of h-BN was exclusively affected by the orientation of the Ni substrate. Detailed discussion about the growth kinetics will be addressed in the next section.


Growth kinetics of white graphene (h-BN) on a planarised Ni foil surface.

Cho H, Park S, Won DI, Kang SO, Pyo SS, Kim DI, Kim SM, Kim HC, Kim MJ - Sci Rep (2015)

Time evolution of h-BN growth morphology on the Ni foils with ECP/LPH2 and ECP/APH2:(a,e) are SEM images of as annealed sample. (b,f), (c,g), and (d,h) are SEM images of h-BN growth for 1 min, 10 min, and 30 min respectively. The first row and the second row are the Ni foil with ECP/LPH2 and ECP/APH2, respectively. (A) and (B) are magnified SEM images taken from the area of Figure (b) and Figure (f) respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4496663&req=5

f3: Time evolution of h-BN growth morphology on the Ni foils with ECP/LPH2 and ECP/APH2:(a,e) are SEM images of as annealed sample. (b,f), (c,g), and (d,h) are SEM images of h-BN growth for 1 min, 10 min, and 30 min respectively. The first row and the second row are the Ni foil with ECP/LPH2 and ECP/APH2, respectively. (A) and (B) are magnified SEM images taken from the area of Figure (b) and Figure (f) respectively.
Mentions: We assumed that the growth feature of h-BN would be affected by the surface roughness of the Ni foil, similar to graphene growth37. The Ni foils went through either ECP/LPH2 or ECP/APH2 before the growth procedure in order to understand how the surface morphology of the Ni surface affects h-BN growth. Dramatic contrast in the h-BN growth kinetics was found, as shown in Figs 3 and 4. While dense triangular domains were observed on the Ni foil with ECP/LPH2 (Fig. 4(a,b)), large area and continuous domains were observed on the Ni foil with ECP/APH2 (Fig. 4(c,d)). Due to the higher surface roughness, small size h-BN domains were formed from the numerous nucleation sites, and thus, distinctive kinetics depending on the crystalline orientation of Ni were not observed in ECP/LPH2 condition. In the case of ECP/APH2, nucleation sites were limited to the grain boundary with scarce nucleation on the surface of the grains, such that the growth kinetics of h-BN was exclusively affected by the orientation of the Ni substrate. Detailed discussion about the growth kinetics will be addressed in the next section.

Bottom Line: The morphology of the surface and the grain orientation of metal catalysts have been considered to be two important factors for the growth of white graphene (h-BN) by chemical vapour deposition (CVD).Atmospheric annealing with hydrogen reduced the nucleation sites of h-BN, which induced a large crystal size mainly grown from the grain boundary with few other nucleation sites in the Ni foil.A higher growth rate was observed from the Ni grains that had the {110} or {100} orientation due to their higher surface energy.

View Article: PubMed Central - PubMed

Affiliation: 1] Soft Innovative Materials Research Center, Korea Institute of Science and Technology, Chudong-ro 92, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905, Republic of Korea [2] Department of Organic Materials and Fiber Engineering, Chonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 561-756, Republic of Korea.

ABSTRACT
The morphology of the surface and the grain orientation of metal catalysts have been considered to be two important factors for the growth of white graphene (h-BN) by chemical vapour deposition (CVD). We report a correlation between the growth rate of h-BN and the orientation of the nickel grains. The surface of the nickel (Ni) foil was first polished by electrochemical polishing (ECP) and subsequently annealed in hydrogen at atmospheric pressure to suppress the effect of the surface morphology. Atmospheric annealing with hydrogen reduced the nucleation sites of h-BN, which induced a large crystal size mainly grown from the grain boundary with few other nucleation sites in the Ni foil. A higher growth rate was observed from the Ni grains that had the {110} or {100} orientation due to their higher surface energy.

No MeSH data available.