TY - JOUR

T1 - Spectroscopic study of nitrogen distribution in N-doped carbon nanotubes and nanofibers synthesized by catalytic ethylene-ammonia decomposition

AU - Svintsitskiy, Dmitry A.

AU - Kibis, Lidiya S.

AU - Smirnov, Dmitry A.

AU - Suboch, Arina N.

AU - Stonkus, Olga A.

AU - Podyacheva, Olga Yu

AU - Boronin, Andrei I.

AU - Ismagilov, Zinfer R.

N1 - Funding Information: This publication has emanated from a research conducted with financial support of the Russian Science Foundation (Grant No. 15-13-10043 ). Also, we thank Helmholtz-Zentrum Berlin for the allocation of synchrotron radiation beamtime. TEY-XAS and PES spectra were obtained in the Russian-German Laboratory at BESSY II (Project # 16204295-ST). Publisher Copyright: © 2017 Elsevier B.V.

PY - 2018/3/30

Y1 - 2018/3/30

N2 - Carbon and nitrogen species on the surface of carbon nanotubes (N-CNTs) and nanofibers (N-CNFs) were studied by X-ray absorption (XAS) and photoelectron spectroscopy (PES) including the analysis of nitrogen distribution over the depth of materials. The study was performed with a series of bamboo-like carbon nanotubes and nanofibers having the platelet-like and herringbone-like morphology. It was shown that the main nitrogen species in the composition of the studied materials are pyridine, pyrrole (and/or amino groups), graphite-like and oxidized states of nitrogen. In distinction to nanofibers, the bamboo-like nanotubes additionally contain molecular nitrogen encapsulated in the internal hollows. Spectral data for different depths of analysis were obtained by varying the energy of incident radiation. Such an approach revealed that N-CNTs are characterized by non-uniform distribution of chemically bound nitrogen species. Thus, nitrogen enrichment was observed on the external surface and in the internal arches of carbon nanotubes. Nitrogen enrichment in the subsurface region was found for N-CNFs, whereas the full depth analysis of N-distribution was limited by a large diameter of nanofibers.

AB - Carbon and nitrogen species on the surface of carbon nanotubes (N-CNTs) and nanofibers (N-CNFs) were studied by X-ray absorption (XAS) and photoelectron spectroscopy (PES) including the analysis of nitrogen distribution over the depth of materials. The study was performed with a series of bamboo-like carbon nanotubes and nanofibers having the platelet-like and herringbone-like morphology. It was shown that the main nitrogen species in the composition of the studied materials are pyridine, pyrrole (and/or amino groups), graphite-like and oxidized states of nitrogen. In distinction to nanofibers, the bamboo-like nanotubes additionally contain molecular nitrogen encapsulated in the internal hollows. Spectral data for different depths of analysis were obtained by varying the energy of incident radiation. Such an approach revealed that N-CNTs are characterized by non-uniform distribution of chemically bound nitrogen species. Thus, nitrogen enrichment was observed on the external surface and in the internal arches of carbon nanotubes. Nitrogen enrichment in the subsurface region was found for N-CNFs, whereas the full depth analysis of N-distribution was limited by a large diameter of nanofibers.

KW - Carbon nanofibers

KW - Carbon nanotubes

KW - Nitrogen doped

KW - Photoelectron spectroscopy

KW - Synchrotron radiation

KW - TEY-XAS

KW - THERMAL-STABILITY

KW - CHEMICAL-VAPOR-DEPOSITION

KW - GRAPHENE

KW - NITRIDE THIN-FILMS

KW - LIQUID-PHASE

KW - TEMPERATURE

KW - REDUCTION

KW - GROWTH

KW - TOTAL-ELECTRON-YIELD

KW - PROBING DEPTH

UR - http://www.scopus.com/inward/record.url?scp=85036466120&partnerID=8YFLogxK

U2 - 10.1016/j.apsusc.2017.11.244

DO - 10.1016/j.apsusc.2017.11.244

M3 - Article

AN - SCOPUS:85036466120

VL - 435

SP - 1273

EP - 1284

JO - Applied Surface Science

JF - Applied Surface Science

SN - 0169-4332

ER -