Ultrasensitive gas detection of large-area boron-doped graphene

Ruitao Lv; Gugang Chen; Qing Li; Amber McCreary; Andrés Botello-Méndez; S. V. Morozov; Liangbo Liang; Xavier Declerck; Nestor Perea-López; David A. Cullen; Simin Feng; Ana Laura Elías; Rodolfo Cruz-Silva; Kazunori Fujisawa; Morinobu Endo; Feiyu Kang; Jean-Christophe Charlier; Vincent Meunier; Minghu Pan; Avetik R. Harutyunyan; Konstantin S. Novoselov; Mauricio Terrones

doi:10.1073/pnas.1505993112

Edited by Manish Chhowalla, Rutgers, Piscataway, NJ, and accepted by the Editorial Board September 28, 2015 (received for review March 26, 2015)

Significance

The gas-sensing performance of graphene could be remarkably enhanced by incorporating dopants into its lattice based on theoretical calculations. However, to date, experimental progress on boron-doped graphene (BG) is still very scarce. Here, we achieved the controlled growth of large-area, high-crystallinity BG sheets and shed light on their electronic features associated with boron dopants at the atomic scale. As a proof-of-concept, it is demonstrated that boron doping in graphene could lead to a much enhanced sensitivity when detecting toxic gases (e.g. NO₂). Our results will open up new avenues for developing high-performance sensors able to detect trace amount of molecules. In addition, other new fascinating properties can be exploited based on as-synthesized large-area BG sheets.

Abstract

Heteroatom doping is an efficient way to modify the chemical and electronic properties of graphene. In particular, boron doping is expected to induce a p-type (boron)-conducting behavior to pristine (nondoped) graphene, which could lead to diverse applications. However, the experimental progress on atomic scale visualization and sensing properties of large-area boron-doped graphene (BG) sheets is still very scarce. This work describes the controlled growth of centimeter size, high-crystallinity BG sheets. Scanning tunneling microscopy and spectroscopy are used to visualize the atomic structure and the local density of states around boron dopants. It is confirmed that BG behaves as a p-type conductor and a unique croissant-like feature is frequently observed within the BG lattice, which is caused by the presence of boron-carbon trimers embedded within the hexagonal lattice. More interestingly, it is demonstrated for the first time that BG exhibits unique sensing capabilities when detecting toxic gases, such as NO₂ and NH₃, being able to detect extremely low concentrations (e.g., parts per trillion, parts per billion). This work envisions that other attractive applications could now be explored based on as-synthesized BG.

Footnotes

↵¹R.L., G.C., Q.L., A.M., and A.B.-M. contributed equally to this work.
↵²To whom correspondence should be addressed. Email: mut11{at}psu.edu.

Author contributions: R.L. and M.T. designed research; R.L., G.C., Q.L., A.M., A.B.-M., S.V.M., L.L., X.D., N.P.-L., D.A.C., S.F., A.L.E., R.C.-S., K.F., J.-C.C., V.M., M.P., and K.S.N. performed research; R.L., G.C., A.M., A.B.-M., S.V.M., L.L., N.P.-L., D.A.C., S.F., A.L.E., R.C.-S., K.F., M.E., M.P., A.R.H., and K.S.N. contributed new reagents/analytic tools; R.L., G.C., Q.L., A.M., A.B.-M., A.L.E., R.C.-S., K.F., J.-C.C., and M.T. analyzed data; and R.L., G.C., A.B.-M., R.C.-S., J.-C.C., and M.T. wrote the paper.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission. M.C. is a guest editor invited by the Editorial Board.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1505993112/-/DCSupplemental.

Freely available online through the PNAS open access option.

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