Two-dimensional polyaniline (C3N) from carbonized organic single crystals in solid state.
The formation of 2D polyaniline (PANI) has attracted considerable interest due to its expected electronic and optoelectronic properties. Although PANI was discovered over 150 y ago, obtaining an atomically well-defined 2D PANI framework has been a longstanding challenge. Here, we describe the synthesis of 2D PANI via the direct pyrolysis of hexaaminobenzene trihydrochloride single crystals in solid state. The 2D PANI consists of three phenyl rings sharing six nitrogen atoms, and its structural unit has the empirical formula of C3N. The topological and electronic structures of the 2D PANI were revealed by scanning tunneling microscopy and scanning tunneling spectroscopy combined with a first-principle density functional theory calculation. The electronic properties of pristine 2D PANI films (undoped) showed ambipolar behaviors with a Dirac point of -37 V and an average conductivity of 0.72 S/cm. After doping with hydrochloric acid, the conductivity jumped to 1.41 × 10(3) S/cm, which is the highest value for doped PANI reported to date. Although the structure of 2D PANI is analogous to graphene, it contains uniformly distributed nitrogen atoms for multifunctionality; hence, we anticipate that 2D PANI has strong potential, from wet chemistry to device applications, beyond linear PANI and other 2D materials.
Center for Dimension-Controllable Organic Frameworks, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea;
Javeed
J
Mahmood
Center for Dimension-Controllable Organic Frameworks, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea; Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, South Korea;
Eun Kwang
EK
Lee
School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea;
Minbok
M
Jung
School of Natural Science, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea.
Dongbin
D
Shin
Center for Dimension-Controllable Organic Frameworks, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea;
Hyun-Jung
HJ
Choi
Center for Dimension-Controllable Organic Frameworks, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea;
Jeong-Min
JM
Seo
Center for Dimension-Controllable Organic Frameworks, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea;
Sun-Min
SM
Jung
School of Natural Science, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea.
Dongwook
D
Kim
Center for Dimension-Controllable Organic Frameworks, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea;
Feng
F
Li
School of Natural Science, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea.
Myoung Soo
MS
Lah
School of Natural Science, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea jbbaek@unist.ac.kr joonhoh@postech.ac.kr shinhj@unist.ac.kr noejung@unist.ac.kr.
Noejung
N
Park
School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea; jbbaek@unist.ac.kr joonhoh@postech.ac.kr shinhj@unist.ac.kr noejung@unist.ac.kr.
Hyung-Joon
HJ
Shin
Department of Chemical Engineering, Pohang University of Science and Technology, Pohang 37673, South Korea; jbbaek@unist.ac.kr joonhoh@postech.ac.kr shinhj@unist.ac.kr noejung@unist.ac.kr.
Joon Hak
JH
Oh
Center for Dimension-Controllable Organic Frameworks, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea; jbbaek@unist.ac.kr joonhoh@postech.ac.kr shinhj@unist.ac.kr noejung@unist.ac.kr.
Jong-Beom
JB
Baek
C3N; nitrogenated graphene; polyaniline; solid-state reaction; two-dimensional