Conductive Metallophthalocyanine Framework Films with High Carrier Mobility as Efficient Chemiresistors

Article abstract of DOI:10.1002/anie.202100717

The poor electrical conductivity of two-dimensional (2D) crystalline frameworks greatly limits their utilization in optoelectronics and sensor technology. Herein, we describe a conductive metallophthalocyanine-based NiPc-CoTAA framework with cobalt(II) te

Full text of DOI:10.1002/anie.202100717

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How to cite: Angew. Chem. Int. Ed. 2021, 60, 10806–10813
International Edition:
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doi.org/10.1002/anie.202100717
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Microporous Materials Hot Paper
Conductive Metallophthalocyanine Framework Films with High
Carrier Mobility as Efficient Chemiresistors
+
+
Yan Yue , Peiyu Cai , Xiaoyi Xu, Hanying Li, Hongzheng Chen, Hong-Cai Zhou,* and
Ning Huang*
[
7]
[8]
[9]
Abstract: The poor electrical conductivity of two-dimensional
2D) crystalline frameworks greatly limits their utilization in
optoelectronics and sensor technology. Herein, we describe
conductive metallophthalocyanine-based NiPc-CoTAA
conduction, optoelectronics, energy storage, and sewage
[
10]
(
treatment. To impart special performances to these frame-
works, the integration of target-oriented functional building
units is generally adopted. For instance, the development of
catalytic frameworks involves embedding, immobilizing, or
loading catalytically active molecules, such as metallopor-
a
framework with cobalt(II) tetraaza[14]annulene linkages.
The high conjugation across the whole network combined
with densely stacked metallophthalocyanine units endows this
material with high electrical conductivity, which can be greatly
enhanced by doping with iodine. The NiPc-CoTAA frame-
work was also fabricated as thin films with different thicknesses
from 100 to 1000 nm by the steam-assisted conversion method.
These films enabled the detection of low-concentration gases
and exhibited remarkable sensitivity and stability. This study
indicates the enormous potential of metallophthalocyanine-
based conductive frameworks in advanced stand-off chemical
sensors and provides a general strategy through tailor-make
molecular design to develop sensitive and stable chemical
sensors for the detection of low-concentration gases.
[11]
[12]
[13]
phyrins,
salen-type complexes,
BINAP ligands,
and
[14]
chiral proline-based units. On the one hand, the introduc-
tion of functional groups endows the frameworks with new
features, greatly enhancing their structural complexity and
functional diversity. On the other hand, the high crystallinity,
high porosity, and high stability of these framework materials
can significantly enhance the specific performance of inte-
grated functional units. Based on these characteristic features
and advantages, a great variety of functionalized MOFs and
COFs are continuously being developed.
Conductive polymers are broadly utilized as an efficient
platform for chemical sensing, which are generally evaluated
using various microelectronic devices. The most frequently
used one are chemiresistors, which are fabricated to measure
the conductometric changes caused by the interaction of the
Introduction
[15]
In past decades, reticular chemistry has aroused a great
deal of interest toward the development of periodically
polymer backbone with electronically analytes. However,
the development of conductive MOFs and COFs remains
a major challenge because most of them lack the low-energy
[
1]
ordered frameworks using various building blocks. This
strategy allows the predesign of target frameworks through
the rational selection of topological structures and building
blocks. Among these materials, metal–organic frameworks
[16]
routes for charge transport or free charge carriers. There-
fore, most of these reticular frameworks behave like electrical
insulators with quite low electrical conductivity
À12
À1 [17]
(
MOFs) and covalent organic frameworks (COFs) constitute
(< 10 Sm ).
To break through this bottleneck, two
the prime examples, which combined the advantages of
intrinsic crystallinity, remarkable porosity, and high structure
strategies have been proposed to facilitate charge transport in
these materials, namely “through-bond” and “through-space”
approaches. Among the conductive MOFs, the 2D MOFs is
[2]
[16]
flexibility. These crystalline materials have been widely
[
3]
utilized in various fields, including gas storage, gas separa-
a particular case of the “through-bond” approach. The
extended 2D p-conjugation could greatly contribute to the
improved electrical conductivity. Recently emerged conduc-
tive MOFs are developed using this approach, such as
[
4]
[5]
[6]
tion, heterogeneous catalysis, chemical sensing, proton
[
+]
[
*] Dr. Y. Yue, X. Xu, Prof. H. Li, Prof. H. Chen, Prof. N. Huang
MOE Key Laboratory of Macromolecular Synthesis and
Functionalization, State Key Laboratory of Silicon Materials
Department of Polymer Science and Engineering
Zhejiang University
[18a]
[18b]
[18c]
Cu (HHTP) ,
Ni (HITP) ,
and Cu HIB .
The spe-
3
2
3
2
3
2
cific stacking pattern of 2D layers is similar with that in 2D
COFs. The periodically ordered p-columns give rises to the
self-sorted donor–acceptor arrays or bicontinuous hetero-
junctions at atomic precision, providing express channels for
Hangzhou, 310027 (China)
E-mail: nhuang@zju.edu.cn
[19]
charge transportation. Several examples have been estab-
lished based on this structural advantage, such as 2D-NiPc-
[
+]
P. Cai, Prof. H.-C. Zhou
Department of Chemistry, Texas A&M University
College Station, TX 77843-3255 (USA)
E-mail: zhou@chem.tamu.edu
[19a]
[19b]
[19c]
BTDA COF,
DMPc-ADI-COFs,
and DA-COF.
Recently, a new conductive framework was successfully
II
+
constructed with the Ni tetraaza[14]annulene complex as
[
] These authors contributed equally to this work.
[20]
the linkage.
The triphenylene-based NiTAA-MOF com-
Supporting information and the ORCID identification number(s) for
the author(s) of this article can be found under:
https://doi.org/10.1002/anie.202100717.
bined the structural advantages of conductive MOFs and
COFs, simultaneously possessing the metal ions and covalent
1
0806
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bonds in the network connectivity. Upon chemical oxidation
with iodine, the electrical conductivity of this material reaches
À1
up to 1 Sm at 300 K. Inspired by this work, we designed and
synthesized
a
metallophthalocyanine-based framework,
which is fully delocalized and highly p-conjugated. This
framework exhibits a high electrical conductivity up to
À1
2
À1
0
.52 Sm with a high carrier mobility up to 0.15 cm Vs .
It is well-known that metallophthalocyanines are widely
utilized as functional units for the preparation of efficient
[
21]
chemiresistors. Therefore, the framework can be fabricated
as thin films and utilized as a high-efficiency chemiresistive
sensor for different gases.
Results and Discussion
Synthesis and Characterization of NiPc-CoTAA
In this study, the metallophthalocyanine-based framework
was synthesized under typical solvothermal conditions using
nickel octaaminophthalocyanine (NiPc[NH ] ), tetramethox-
2
8
ypropane (TMP), and cobalt acetate tetrahydrate as sub-
strates (Scheme 1). The synthesis was carried out under
a basic condition with triethylamine as catalyst at 1208C for
5
days. The resulting 2D NiPc-CoTAA framework consisted
of nickel phthalocyanines as knots and cobalt tetraaza-
14]annulenes as linkers (Figure 1a,b). It was obtained as
[
a black powder in a good yield of 78% after rinsing with
various solvents in Soxhlet extractor. The cobalt tetraaza-
[
14]annulene model complex was also synthesized and
obtained as single crystals. The model complex is completely
planar, facilitating the formation of closely aggregated 2D
layers (Figure S1). The crystalline structure of the NiPc-
CoTAA framework was resolved by its powder X-ray
diffraction (PXRD) patterns in combination with theoretical
simulation. It exhibited a series of PXRD patterns at 4.908,
Scheme 1. Synthesis of NiPc-CoTAA using NiPc[NH
] , TMP, and Co-
2 8
(
OAc) ·4H O under solvothermal conditions. DMF=N,N-dimethylfor-
2
2
mamide.
6
.968, 9.828, and 25.628, which can be attributed to the (100),
(
200), (300), and (001) facets, respectively (Figure 1c). The
Pawley refinement generates a set of PXRD patterns, which
are close to the experimental results. The structural simu-
lation based on the P4/MMM space group offers a set of
lattice parameters, namely a = b = g = 908, a = b = 18.0195 Š,
and c = 3.4815 Š (Table S1). The AA stacking mode (Fig-
ure 1d) produces a sequence of diffraction peaks, which
corresponds well with the experimentally observed PXRD
results. On the contrary, the diffraction peaks derived from
the AB stacking mode (Figure 1e) deviate a lot with the
experimental patterns. The adjacent layer distance was
determined as 3.48 Š, which was similar to those of other
the elemental composition of 2D NiPc-CoTAA was in high
accordance with its theoretical values (Figure S4, Table S2).
High resolution transmission electron microscopy (HR-
TEM) image supplies direct viewing of tetragonal pores and
exhibited obvious lattice fringes with a characteristic spacing
distance around 1.0 nm (Figure S5). Thermogravimetric anal-
ysis (TGA) showed this framework was thermally stable up to
4508C under nitrogen atmosphere (Figure S6). The chemical
composition of 2D NiPc-CoTAAwas investigated using X-ray
photoelectron spectroscopy (XPS). A series of resonance
peaks of C, N, O, Ni, and Co were found in the spectrum
(Figure S7). The existence of the O signal can be attributed to
[18,19]
2
D COFs and MOFs.
To investigate the property of 2D NiPc-CoTAA, it was
unambiguously characterized using a variety of analysis
methods. In the Fourier transform infrared (FTIR) spectrum,
the H O molecules trapped in the porous framework or
2
coordinated H O to Co or Ni metal centers. For example, four
2
À1
the appearance of a strong vibration band at 1596 cm
characteristic peaks at 781 and 796 eV were ascribed to Co
II
revealed the formation of Co tetraaza[14]annulene (Fig-
3d3/2 and Co 3d , respectively. The other two signals at 786
2/1
ure S2). Field emission scanning electron microscopy (FE-
SEM) image indicated it adopted an irregularly granular
morphology with a size around 54 mm (Figure S3). Energy
dispersive X-ray (EDX) mapping analysis demonstrated that
and 803 eV were attributed to Co 3d3/2 and Co 3d2/1 satellite
peaks, respectively (Figure 2a). These results indicated all the
Co species in the NiPc-CoTAA network had a valence of + 2
instead of other valence states. At the same time, the XPS
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Figure 1. a) Top view and b) side view of the 2D crystalline NiPc-CoTAA framework. c) PXRD patterns of NiPc-CoTAA (black curve, experimental;
red curve, simulated; blue curve, difference between experimental and simulated curves; green curve, AA stacking; brown curve, AB stacking).
Unit cells of the d) AA and e) AB stacking mode (H white, C gray, N blue, Ni orange, Co red).
spectrum of Ni exhibited two characteristic signals at 856 and
74 eV, which were assigned to the Ni 3d3/2 and Ni 3d1/2
peaks. After soaking in hexane, methanol, water, DMF, HCl
(1 M), and NaOH (1 M) aqueous solutions overnight, NiPc-
CoTAA retained its high crystallinity with almost unchanged
diffraction positions and intensity (Figure S15). In addition,
the residual weight of the soaked NiPc-CoTAA samples was
investigated to determine their weight loss. Notably, the
residual weight percentages were calculated as 100%, 99%,
100%, and 98% for the soaked samples in hexane, methanol,
water, and DMF, respectively (Figure S16). In comparison,
the residual proportion was determined as 96% and 93%
after soaking in HCl (1 M) and NaOH (1 M) solutions,
8
electrons, respectively (Figure S8). The other weak signals
at 862 and 880 eV were assigned to Ni 3d3/2 and Ni 3d1/2
satellite peaks, respectively. This analysis result indicated two
valence states of Ni existing in the NiPc-CoTAA framework,
II
0
namely Ni and Ni . The molar ratio was calculated as 86/14 of
II
0
0
Ni to Ni . The appearance of Ni is possibly due to the
reducibility of Et N during the solvothermal process. The
3
sample was dispersed in aqueous HCl (6 M) solution for
0
3
days. However, no obvious Ni particles were observed in
II
HR-TEM (Figure S9), EDX (Figure S10), and XPS spectra
Figures S11 and S12). It is speculated that a small portion of
respectively. The results demonstrated that the Co tetraaza-
(
[14]annulene linked framework possessed high chemical
robustness under certain conditions, benefiting from the
remarkable stability of tetraaza[14]annulene linkage and the
accumulated 2D layer structures.
0
Ni might exist as defects or single atoms instead of nano-
particles in the framework. Furthermore, the porosity of the
NiPc-CoTAA framework was evaluated using nitrogen sorp-
tion measurement at 77 K. It exhibited a type-I sorption
isotherm (Figure S13), which is a characteristic curve of
microporous materials. The Brunauer–Emmett–Teller (BET)
Electronic Band Diagram
2
À1
surface areas of NiPc-CoTAA was calculated as 186 m g .
The pore size of NiPc-CoTAA was estimated around 0.9 nm
The extended p-conjugation across the framework could
render NiPc-CoTAA promising as an organic semiconductor
or conductor material (Figure 2b). As shown in Figure 2c, the
electronic band structure of NiPc-CoTAA monolayer was
investigated using DFT calculation. The conduction band
(CB) and valence band (VB) in the framework is nearly
dispersionless, demonstrating the charge transport in the
monolayer plane is void. The band gap for NiPc-CoTAA is
calculated as 0.86 eV. The computed result through space
(
(
Figure S14), which coincided well with the theoretical value
1.0 nm).
Chemical Stability
The chemical stability of 2D NiPc-CoTAA framework in
different solvents was evaluated using the intensity of PXRD
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Figure 2. a) XPS spectrum of the cobalt species in the NiPc-CoTAA framework. b) Unit cell of NiPc-CoTAA and its first Brillouin zone. c) Calculated
electronic band structure of NiPc-CoTAA. d) Electronic adsorption spectrum of NiPc-CoTAA (black curve) and iodine-doped NiPc-CoTAA (red
curve). e) Temperature-dependent current plot of a pressed NiPc-CoTAA pellet measured by a four-point probe at temperatures from 293 to 393 K
with an applied voltage of 1 V. The inset exhibits the Arrhenius plot of the current versus temperature. f) EPR spectrum of NiPc-CoTAA (black
curve) and the iodine-coped NiPc-CoTAA framework (red curve).
charge transport property is consistent with those found in
other phthalocyanine- and porphyrin-based COFs,
the metal tetraaza[14]annulene units can be partially oxidized
by iodine, giving rise to the formation of conductive macro-
[11c,22]
[23]
which exhibited high carrier mobility along the direction of
the stacking due to the formation of periodic p-columns. In
addition, NiPc-CoTAA exhibited a broad electronic adsorp-
tion band up to 1100 nm with the maximum adsorption peak
at 702 nm, confirming the 2D NiPc-CoTAA had a very low
band gap around 0.86 eV (Figure 2d).
cycles.
Enlightened by this specific property, we doped
NiPc-CoTAA using iodine in an airtight vessel at 808C
overnight. As shown in the EPR spectrum (Figure 2 f), the
pristine NiPc-CoTAA exhibited a series of signals with a g
center value of 2.0048, which can be attributed to the free
radical in the framework. The iodine-doped NiPc-CoTAA
also showed one principal peak of free radicals at the g value
of 2.0048, while its intensity is eight times that of pristine
samples, demonstrating the greatly increased content of free
radicals. The disappearance of other coupling peaks was due
to sharply increased radical signal, which was overwhelming
to other coupling peaks. In the Raman spectrum, the iodine-
doped NiPc-CoTAA exhibited two characteristic peaks at
Electrical Conductivity
The Hall effect measurement was conducted to evaluate
the electrical conductivity of NiPc-CoTAA. It was deter-
mined as a p-type semiconductor with a charge carrier density
1
3
À3
2
À1
À1
of 2.14 ” 10 cm and a carrier mobility of 0.15 cm Vs . The
mobility of NiPc-CoTAA ranks as one of the highest values
and is comparable with those of several landmark COF and
110, 113, and 167 cm (Figure S17), which were assigned to
À
À
the signals of symmetric I3 and I5 ions. The XPS analysis
result also confirmed the content and valence of iodine in the
doped NiPc-CoTAA (Figures S18–S21). In addition, the
iodine-doped sample exhibited a slightly wider electronic
absorption up to 1100 nm (Figure 2d). Notably, the electrical
conductivity of the iodine-doped NiPc-CoTAA reached up to
[18–20]
MOF semiconductors (Table S3).
Furthermore, its con-
ductivity was evaluated using the four-point probe measure-
ment on a pressed powder pellet. The DC (bulk) conductivity
À3
À1
was determined as 8.16 ” 10 Sm at 298 K. Its activation
energy was calculated as 0.33 eV based on the temperature-
dependent Arrhenius curve (Figure 2e). It is well-known that
À1
0.52 Sm , which was approximately 64-fold improvement of
its pristine counterpart and ranked as one of the highest
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values among reported 2D framework materials (Table S3).
Compared with other frameworks, NiPc-CoTAA is highly
conductive mainly owing to several factors. Firstly, NiPc-
CoTAA has a fully p-conjugated structure, which spans the
on a platform in the vessel. A droplet of precursor solution
was evenly deposited on the ITO substrate. The vessel was
sealed and heated to 1208C for 12 h. After cooling down to
room temperature, the ITO substrate was taken out and
washed with acetone. The NiPc-CoTAA thin films were
obtained upon drying under vacuum for 1 h. Notably, the
thickness of the film can be well controlled from 100 to
1000 nm by adjusting the number of droplets (Figure S23).
Owing to the poor mechanical properties of NiPc-CoTAA,
the thinner films (< 100 nm) are very fragile and easily to be
broken into flakelets. We did not obtain the films with
thickness of tens of nanometers. The wide-spread NiPc-
CoTAA film was obtained with smooth, compact, and
uniform surface (Figure 3a). As shown in Figure 3b, the
average surface roughness was around 20 nm over an area of
2
ns.
D sheets and facilitates the migration of delocalized electro-
[
22a,24a]
Secondly, the phthalocyanine and cobalt tetraaza-
[
14]annulene units stack as columns in an eclipsed manner
and offer desirable conduction pathways for charge car-
[24b]
riers.
Thirdly, the oxidation of the metal tetraaza-
[
14]annulene units leads to the formation of conductive
[
20,23]
macrocycles.
However, few frameworks can simultane-
ously satisfy all these requirements.
Film Preparation
5
mm ” 5 mm. The high-quality film provides a reliable plat-
Inspired by the high conductivity of NiPc-CoTAA, we
attempted to prepare its thin films for the fabrication of high-
performance sensing devices. The film was prepared using the
steam-assisted conversion (VAC) approach (Figure S22),
which has been reported by Medina for the preparation of
form for the preparation of efficient sensor devices.
Sensing Performance for Gases
[25]
highly oriented MOF thin films.
The NiPc[NH ] , TMP,
The electrical conductivity of the NiPc-CoTAA film was
further measured using the current–voltage (I–V) method,
which was carried out using an interdigitated array (IDA) Au
electrode. The electrical conductivity of these films was
2
8
cobalt acetate tetrahydrate, and triethylamine were dissolved
in DMF as the precursor solution. A mixture of DMF and
triethylamine (20:1, v/v) was added into a vessel as the vapor
source. Then an ITO substrate (1.0 cm ” 1.5 cm) was placed
À3
À1
calculated to be 6.67 ” 10 Sm , which was nearly triple that
Figure 3. a) FE-SEM image of a NiPc-CoTAA thin film with a thickness of 100 nm. b) 2D AFM image of the 100 nm NiPc-CoTAA thin film. c) I–V
curves of NiPc-CoTAA films with different thicknesses from 100 to 500 nm (black, 100 nm; purple, 150 nm; blue, 270 nm; cyan, 500 nm; green,
6
70 nm; orange, 800 nm; red, 1000 nm). d) Chemiresistive detection of NO using NiPc-CoTAA films on a gold IDA electrode. e) Time-dependent
2
response–recovery current plot of the 500 nm NiPc-CoTAA film at NO concentrations from 1 to 40 ppm at 298 K. The inset shows the linear
2
relation between R% and the NO concentration at 298 K. f) Responsivity and sensitivity of the 500 nm NiPc-CoTAA film towards different gases
2
(
NO , NO, NH , H S, and H ) at 1 ppm (red bar, R%; blue bar, S%).
2 3 2 2
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of the pressed pellets owing to the more compact film
nanoscale textures or higher crystal orientations. The inter-
grown framework crystallites could lead to more flawless tile
patterns. As shown in Figure 3c, the current increase mo-
mentum was moderated along with the increase of thickness
under a bias of 5.0 V, indicating the homogeneity of the films.
In addition, the analysis results illustrated that the electrical
conductance of the films was increased with their thickness in
good linearity (Figure S24).
towards NO and NO, the film showed a negative response
when exposed to the electron-donating NH3 and H2S
2
atmosphere (Figures S28–S31). The R% and S% values were
À1
calculated as 3.1% and 1.2% ppm toward NH , and as
3
À1
8.2% and 3.3% ppm for H S, respectively. The intermo-
2
lecular hydrogen bonding with nitrogen atoms in the network
is possibly formed, leading to a kinetic barrier against the
diffusion of these electron-donating gases. However, there
was no obvious response observed for the detection of H2
(Figure S32). The NiPc-CoTAA thin film exhibited a superior
NO sensing selectivity to that of NO, NH , H S, and H at
To investigate the possibility of utilizing the NiPc-CoTAA
films for gas sensing, we prepared an electronic device with
the 500 nm NiPc-CoTAA thin film (Figure 3d). Several gases,
including NO , NO, NH , H S, and H were employed as
2
3
2
2
298 K (Figure 3 f). All these results demonstrated that the 2D
NiPc-CoTAA film not only exhibited high sensitivity but also
excellent selectivity as chemiresistive sensors.
2
3
2
2
analytes to evaluate the response/recovery ability of the
device. These analytes have different oxidation–reduction
quality and coordination ability towards the metal centers,
which could provoke a change in the electrical conductivity of Conclusion
NiPc-CoTAA. Upon exposure to NO2 gas at different
concentrations (1–40 ppm) at 298 K, the device exhibited
different current responses. In one duty cycle, the dynamic
response time was set as 5 min and the static recovery time
varied from 5 to 60 min to completely release the NO2
analyte. As shown in Figure 3e, the current intensity was
increased along with the exposure time prolonging but
decreased as recovery proceeded, illustrating that the p-type
responsivity of NiPc-CoTAA to the oxidizing analyte. To
quantitatively evaluate the responsivity (R%) at different
concentrations, the percentage of current change was calcu-
lated according to the equation: R% = [(I ÀI)/I] ” 100%,
In summary, we developed a new kind of conductive
phthalocyanine-based framework material, which was con-
nected with a conjugated tetraaza[14]annulene linkage. We
unambiguously studied the crystallinity, stability, and con-
ductivity of NiPc-CoTAA framework, with a variety of
characterization methods. The high conjugation and densely
stacked p-units rendered this material with a low band gap of
0.86 eV. The electrical conductivity of NiPc-CoTAA was
À3
À1
measured as high as 8.16 ” 10 Sm , which can be further
À1
enhanced to 0.52 Sm after doping with iodine. The high
conductivity and embedded metal phthalocyanine units
makes this material promising for the detection of toxic
gases. To fulfill this target, we prepared the NiPc-CoTAA thin
films with tunable thicknesses from 100 to 1000 nm using the
VAC method. The obtained films are of a high degree of
crystal orientation and high electrical conductivity. Further-
more, the films exhibited significant sensitivity towards
several redox gases. This work would constitute an important
step during the development of conductive frameworks and
pave the way for their applications in various practical fields.
t
i
i
where I represents the initial current intensity and I indicates
i
t
the current density after exposure for 5 min to NO atmos-
2
phere. The almost linear fitting curve demonstrates the
interaction between NO and the film is first-order kinetic
2
[
26]
(
Figure 3e, inset). Consequently, the concentration of NO2
can be quantitively analyzed using the film. The R% values
were calculated as 215%, 352%, 602%, 902%, 1292%, and
1
4
658% at the NO concentrations of 1, 5, 10, 20, 30, and
0 ppm, respectively. This result revealed that the NiPc-
2
CoTAA has a superior sensitivity, which is comparable with
other landmark materials, such as COF-DC-8 and UPC-
[
22a,27]
H4.
Consequently, the AA stacking mode which facil- Acknowledgements
itates the orbital overlap in association of periodically
crystalline and porous structures which enhances the surface
area contributes to the remarkable sensing performance. In
N.H. acknowledges support by the research start-up fund of
Zhejiang University. H.-C.Z. acknowledges support by the
U.S. Department of Energy, Office of Science, Office of Basic
Energy Sciences (DE-SC0001015), the Robert A. Welch
Foundation through a Welch Endowed Chair to H.-C.Z. (A-
0030), and a National Science Foundation Graduate Research
Fellowship under Grant No. DGE:1252521.
addition, the sensitivity (S%) of the film was evaluated as
À1
3
7.6 ppm using the slope of linear correlation between
responsivity and the concentration of NO . Notably, the NiPc-
2
CoTAA film can be recycled over five times without
significant decrease in current density (Figure S25). The
sensing performance of thin films with various thickness was
also evaluated, while they exhibited inferior responsibility,
sensitivity, and reversibility.
Conflict of interest
Inspired by the high sensing performance of NiPc-CoTAA
thin films, we further studied its response/recovery behavior
towards NO, NH , H S, and H under the same conditions.
The authors declare no conflict of interest.
3
2
2
Owing to the weaker oxidation and coordination ability of
Keywords: conducting materials · conjugated polymers ·
covalent organic frameworks · metal–organic frameworks ·
porous polymers
NO, the film exhibited a lower response plot with R% and S%
À1
values of 27% and 12.7% ppm (Figure 3 f, Figures S26 and
S27), respectively. In contrast with the positive responses
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Qin, J. Li, Y. Zhang, Q. Wang, D. Jiang, H.-C. Zhou, J. Am.
Chem. Soc. 2017, 139, 18590 – 18597; c) X. Xu, S. Wang, Y. Yue,
N. Huang, ACS Appl. Mater. Interfaces 2020, 12, 37427 – 37434;
d) J.-L. Shi, R. Chen, H. Hao, C. Wang, X. Lang, Angew. Chem.
Int. Ed. 2020, 59, 9088 – 9093; Angew. Chem. 2020, 132, 9173 –
[
[
1] a) O. M. Yaghi, J. Am. Chem. Soc. 2016, 138, 15507 – 15509;
b) O. M. Yaghi, Nano Lett. 2020, 20, 8432 – 8434.
2] a) H.-C. Zhou, J. R. Long, O. M. Yaghi, Chem. Rev. 2012, 112,
6
73 – 674; b) N. Huang, P. Wang, D. Jiang, Nat. Rev. Mater. 2016,
1, 16068.
9
178.
12] a) J. Li, Y. Fan, Y. Ren, Y. Liao, C. Qi, H. Jiang, Inorg. Chem.
018, 57, 1203 – 1212; b) M. H. Beyzavi, R. C. Klet, S. Tussup-
[
[
[
[
[
3] a) Y. Li, R. T. Yang, Langmuir 2007, 23, 12937 – 12944; b) A. J.
Rieth, M. Dinc a˘ , J. Am. Chem. Soc. 2018, 140, 3461 – 3466; c) Y.
Wang, X. Jia, H. Yang, Y. Wang, X. Chen, A. N. Hong, J. Li, X.
Bu, P. Feng, Angew. Chem. Int. Ed. 2020, 59, 19027 – 19030;
Angew. Chem. 2020, 132, 19189 – 19192; d) N. Huang, X. Chen,
R. Krishna, D. Jiang, Angew. Chem. Int. Ed. 2015, 54, 2986 –
[
2
bayev, J. Borycz, N. A. Vermeulen, C. J. Cramer, J. F. Stoddart,
J. T. Hupp, O. K. Farha, J. Am. Chem. Soc. 2014, 136, 15861 –
1
5864; c) L.-H. Li, X.-L. Feng, X.-H. Cui, Y.-X. Ma, S.-Y. Ding,
W. Wang, J. Am. Chem. Soc. 2017, 139, 6042 – 6045; d) S. Yan, X.
Guan, H. Li, D. Li, M. Xue, Y. Yan, V. Valtchev, S. Qiu, Q. Fang,
J. Am. Chem. Soc. 2019, 141, 2920 – 2924.
2
990; Angew. Chem. 2015, 127, 3029 – 3033; e) N. Huang, R.
Krishna, D. Jiang, J. Am. Chem. Soc. 2015, 137, 7079 – 7082.
4] a) J. Y. S. Lin, Science 2016, 353, 121 – 122; b) R.-B. Lin, S. Xiang,
H. Xing, W. Zhou, B. Chen, Coord. Chem. Rev. 2019, 378, 87 –
[
[
13] a) T. Sawano, N. C. Thacker, Z. Lin, A. R. McIsaac, W. Lin, J.
Am. Chem. Soc. 2015, 137, 12241 – 12248; b) M. J. Kalmutzki, N.
Hanikel, O. M. Yaghi, Sci. Adv. 2018, 4, eaat9180.
14] a) C. Kutzscher, G. Nickerl, I. Senkovska, V. Bon, S. Kaskel,
Chem. Mater. 2016, 28, 2573 – 2580; b) V. Pascanu, G. G. Miera,
A. K. Inge, B. Martín-Matute, J. Am. Chem. Soc. 2019, 141,
1
3
03; c) J.-R. Li, R. J. Kuppler, H.-C. Zhou, Chem. Soc. Rev. 2009,
8, 1477 – 1504; d) H. Fan, A. Mundstock, A. Feldhoff, A.
Knebel, J. Gu, H. Meng, J. Caro, J. Am. Chem. Soc. 2018, 140,
0094 – 10098; e) S. Yuan, X. Li, J. Zhu, G. Zhang, P. V.
Puyvelde, B. V. der Bruggen, Chem. Soc. Rev. 2019, 48, 2665 –
681.
5] a) L. Zhu, X.-Q. Liu, H.-L. Jiang, L.-B. Sun, Chem. Rev. 2017,
17, 8129 – 8176; b) A. Bavykina, N. Kolobov, I. S. Khan, J. A.
1
7
9
223 – 7234; c) H. Xu, J. Gao, D. Jiang, Nat. Chem. 2015, 7, 905 –
12.
2
[
15] a) T. M. Swager, K. A. Mirica, Chem. Rev. 2019, 119, 1 – 2; b) M.
Ko, L. Mendecki, K. A. Mirica, Chem. Commun. 2018, 54, 7873 –
1
Bau, A. Ramirez, J. Gascon, Chem. Rev. 2020, 120, 8468 – 8535;
c) J. Guo, D. Jiang, ACS Cent. Sci. 2020, 6, 869 – 879; d) T.
Kundu, J. Wang, Y. Cheng, Y. Du, Y. Qian, G. Liu, D. Zhao,
Dalton Trans. 2018, 47, 13824 – 13829; e) N. Huang, K. H. Lee, Y.
Yue, X. Xu, S. Irle, Q. Jiang, D. Jiang, Angew. Chem. Int. Ed.
7
1
1
891; c) U. Lange, V. M. Mirsky, Anal. Chim. Acta 2011, 687,
05 – 113; d) W.-T. Koo, J.-S. Jang, I.-D. Kim, Chem 2019, 5,
938 – 1963.
[
[
[
16] a) L. Sun, M. G. Campbell, M. Dinc a˘ , Angew. Chem. Int. Ed.
016, 55, 3566 – 3579; Angew. Chem. 2016, 128, 3628 – 3642;
b) L. S. Xie, G. Skorupskii, M. Dinc a˘ , Chem. Rev. 2020, 120,
536 – 8580.
17] a) H.-C. Zhou, S. Kitagawa, Chem. Soc. Rev. 2014, 43, 5415 –
418; b) H. Furukawa, K. E. Cordova, M. OꢀKeeffe, O. M.
2
2
020, 59, 16587 – 16593; Angew. Chem. 2020, 132, 16730 – 16736.
6] a) H.-Y. Li, S.-N. Zhao, S.-Q. Zang, J. Li, Chem. Soc. Rev. 2020,
9, 6364 – 6401; b) L. E. Kreno, K. Leong, O. K. Farha, M.
Allendorf, R. P. Van Duyne, J. T. Hupp, Chem. Rev. 2012, 112,
105 – 1125; c) Q. Gao, X. Li, G.-H. Ning, K. Leng, B. Tian, C.
Liu, W. Tang, H.-S. Xu, K. P. Loh, Chem. Commun. 2018, 54,
349 – 2352; d) Z. Li, N. Huang, K. H. Lee, Y. Feng, S. Tao, Q.
Jiang, Y. Nagao, S. Irle, D. Jiang, J. Am. Chem. Soc. 2018, 140,
2374 – 12377.
7] a) G. K. H. Shimizu, J. M. Taylor, S. Kim, Science 2013, 341, 354 –
8
4
5
1
Yaghi, Science 2013, 341, 1230444; c) S. J. Lyle, P. J. Waller, O. M.
Yaghi, Trends Chem. 2019, 1, 172 – 184.
2
18] a) M. G. Campbell, D. Sheberla, S. F. Liu, T. M. Swager, M.
Dinc a˘ , Angew. Chem. Int. Ed. 2015, 54, 4349 – 4352; Angew.
Chem. 2015, 127, 4423 – 4426; b) E. M. Miner, T. Fukushima, D.
Sheberla, L. Sun, Y. Surendranath, M. Dinc a˘ , Nat. Commun.
1
3
8
55; b) D.-W. Lim, H. Kitagawa, Chem. Rev. 2020, 120, 8416 –
467; c) X. Wu, Y.-L. Hong, B. Xu, Y. Nishiyama, W. Jiang, J.
2
016, 7, 10942; c) I. Stassen, J.-H. Dou, C. Hendon, M. Dinc a˘ ,
ACS Cent. Sci. 2019, 5, 1425 – 1431.
Zhu, G. Zhang, S. Kitagawa, S. Horike, J. Am. Chem. Soc. 2020,
42, 14357 – 14364; d) Q. Xu, S. Tao, Q. Jiang, D. Jiang, J. Am.
[
19] a) X. Ding, L. Chen, Y. Honsho, X. Feng, O. Saengsawang, J.
Guo, A. Saeki, S. Seki, S. Irle, S. Nagase, V. Parasuk, D. Jiang, J.
Am. Chem. Soc. 2011, 133, 14510 – 14513; b) S. Jin, M. Supur, M.
Addicoat, K. Furukawa, L. Chen, T. Nakamura, S. Fukuzumi, S.
Irle, D. Jiang, J. Am. Chem. Soc. 2015, 137, 7817 – 7827; c) X.
Feng, L. Chen, Y. Honsho, O. Saengsawang, L. Liu, L. Wang, A.
Saeki, S. Irle, S. Seki, Y. Dong, D. Jiang, Adv. Mater. 2012, 24,
1
Chem. Soc. 2018, 140, 7429 – 7432.
[
[
8] a) Y. Zhao, X.-G. Yang, X.-M. Lu, C.-D. Yang, N.-N. Fan, Z.-T.
Yang, L.-Y. Wang, L.-F. Ma, Inorg. Chem. 2019, 58, 6215 – 6221;
b) Y. Cui, J. Zhang, H. He, G. Qian, Chem. Soc. Rev. 2018, 47,
5
740 – 5785; c) S. Wang, X. Xu, Y. Yue, K. Yu, Q. Shui, N. Huang,
H. Chen, Small Struct. 2020, 1, 2000021.
3
026 – 3031.
9] a) S. Zheng, X. Li, B. Yan, Q. Hu, Y. Xu, X. Xiao, H. Xue, H.
Pang, Adv. Energy Mater. 2017, 7, 1602733; b) T. Qiu, Z. Liang,
W. Guo, H. Tabassum, S. Gao, R. Zou, ACS Energy Lett. 2020, 5,
[
20] Y. Jiang, I. Oh, S. H. Joo, O. Buyukcakir, X. Chen, S. H. Lee, M.
Huang, W. K. Seong, S. K. Kwak, J.-W. Yoo, R. S. Ruoff, J. Am.
Chem. Soc. 2019, 141, 16884 – 16893.
21] a) F. I. Bohrer, C. N. Colesniuc, J. Park, M. E. Ruidiaz, I. K.
Schuller, A. C. Kummel, W. C. Trogler, J. Am. Chem. Soc. 2009,
131, 478 – 485; b) F. I. Bohrer, C. N. Colesniuc, J. Park, I. K.
Schuller, A. C. Kummel, W. C. Trogler, J. Am. Chem. Soc. 2008,
130, 3712 – 3713; c) K.-C. Ho, Y.-H. Tsou, Sens. Actuators B
2001, 77, 253 – 259; d) C. J. Liu, J. J. Shih, Y. H. Ju, Sens.
Actuators B 2004, 99, 344 – 349.
[22] a) Z. Meng, R. M. Stolz, K. A. Mirica, J. Am. Chem. Soc. 2019,
141, 11929 – 11937; b) M.-D. Zhang, D.-H. Si, J.-D. Yi, S.-S. Zhao,
Y.-B. Huang, R. Cao, Small 2020, 16, 2005254.
[23] a) P. J. Spellane, L. V. Interrante, R. K. Kullnig, F. S. Tham,
Inorg. Chem. 1989, 28, 1587 – 1590; b) A. M. Whyte, Y. Shuku,
G. S. Nichol, M. M. Matsushita, K. Awaga, N. Robertson, J.
Mater. Chem. 2012, 22, 17967.
5
20 – 532; c) S. B. Alahakoon, C. M. Thompson, G. Occhialini,
[
R. A. Smaldone, ChemSusChem 2017, 10, 2116 – 2129; d) C. R.
DeBlase, K. E. Silberstein, T.-T. Truong, H. D. AbruÇa, W. R.
Dichtel, J. Am. Chem. Soc. 2013, 135, 16821 – 16824.
[
[
10] a) A. V. Desai, B. Manna, A. Karmakar, A. Sahu, S. K. Ghosh,
Angew. Chem. Int. Ed. 2016, 55, 7811 – 7815; Angew. Chem.
2
016, 128, 7942 – 7946; b) C.-C. Wang, J.-R. Li, X.-L. Lv, Y.-Q.
Zhang, G. Guo, Energy Environ. Sci. 2014, 7, 2831 – 2867; c) N.
Huang, L. Zhai, H. Xu, D. Jiang, J. Am. Chem. Soc. 2017, 139,
2
428 – 2434; d) N. Huang, P. Wang, M. A. Addicoat, T. Heine, D.
Jiang, Angew. Chem. Int. Ed. 2017, 56, 4982 – 4986; Angew.
Chem. 2017, 129, 5064 – 5068.
11] a) N. Huang, K. Wang, H. Drake, P. Cai, J. Pang, J. Li, S. Che, L.
Huang, Q. Wang, H.-C. Zhou, J. Am. Chem. Soc. 2018, 140,
6
383 – 6390; b) N. Huang, S. Yuan, H. Drake, X. Yang, J. Pang, J.
1
0812 www.angewandte.org
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Angewandte
Research Articles
Chemie
[
[
24] a) J. Guo, Y. Xu, S. Jin, L. Chen, T. Kaji, Y. Honsho, M. A.
[26] F. I. Bohrer, A. Sharoni, C. Colesniuc, J. Park, I. K. Schuller,
Addicoat, J. Kim, A. Saeki, H. Ihee, S. Seki, S. Irle, M. Hiramoto,
J. Gao, D. Jiang, Nat. Commun. 2013, 4, 2736; b) X. Feng, L. Liu,
Y. Honsho, A. Saeki, S. Seki, S. Irle, Y. Dong, A. Nagai, D. Jiang,
Angew. Chem. Int. Ed. 2012, 51, 2618 – 2622; Angew. Chem.
A. C. Kummel, W. C. Trogler, J. Am. Chem. Soc. 2007, 129,
5640 – 5646.
[27] Y. Wang, D. Liu, J. Yin, Y. Shang, J. Du, Z. Kang, R. Wang, Y.
Chen, D. Sun, J. Jiang, Chem. Commun. 2020, 56, 703 – 706.
2
012, 124, 2672 – 2676.
25] E. Virmani, J. M. Rotter, A. Mähringer, T. von Zons, A. Godt, T.
Bein, S. Wuttke, D. D. Medina, J. Am. Chem. Soc. 2018, 140,
Manuscript received: January 16, 2021
Accepted manuscript online: February 26, 2021
Version of record online: April 1, 2021
4
812 – 4819.
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