Accurate chemical analysis of graphene-based materials using X-ray photoelectron spectroscopy
Journal article, 2019

A simple, fast and general protocol for quantitative analysis of X-ray photoelectron spectroscopy (XPS) data provides accurate estimations of chemical species in graphene and related materials (GRMs). XPS data are commonly used to estimate the quality of and defects in graphene and graphene oxide (GO), by comparing carbon and oxygen 1s XPS peaks, obtaining an O/C ratio. This approach, however, cannot be used in the presence of extraneous oxygen contamination.

The protocol, based on quantitative line-shape analysis of C 1s signals, uses asymmetric pseudo- Voigt line-shapes (APV), in contrast to Gaussian-based approaches conventionally used in fitting XPS spectra, thus allowing better accuracy in quantifying C 1s contributions from graphitic carbon (sp2), defects (sp3 carbon), carbons bonded to hydroxyl and epoxy groups, and from carbonyl and carboxyl groups. The APV protocol was evaluated on GRMs with O/C ratios ranging from 0.02 to 0.30 with film thicknesses from monolayers to bulk-like (>30nm) layers and also applied to previously published data, showing better results compared to those from conventional XPS fitting protocols.

Based uniquely on C 1s data, the APV protocol can quantify O/C ratio and the presence of specific functional groups in GRMs even on SiOx, substrates, or in samples containing water.

graphene

graphite

XPS

Author

Alessandro Kovtun

National Research Council of Italy (CNR)

Derek Jones

National Research Council of Italy (CNR)

Simone Dell'Elce

National Research Council of Italy (CNR)

E. Treossi

National Research Council of Italy (CNR)

A. Liscio

National Research Council of Italy (CNR)

Vincenzo Palermo

Chalmers, Industrial and Materials Science, Materials and manufacture

Carbon

0008-6223 (ISSN)

Vol. 143 268-275

Subject Categories

Inorganic Chemistry

Materials Chemistry

Other Chemistry Topics

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Production

Materials Science

Infrastructure

Chalmers Materials Analysis Laboratory

DOI

10.1016/j.carbon.2018.11.012

More information

Latest update

2/18/2019