The behavior of the monoxide carbon (CO) adsorbed on the external surface of H-capped (6,0) zigzag
single-walled aluminum nitride nanotube was studied under the parallel and transverse electric fields
with strengths 0-140 × 10-4 a.u. by using density functional calculations. Geometry optimizations were carried
out at the B3LYP/6-31G* level of theory using the Gaussian 03 suite of programs. The binding energies
obtained from these calculations at different applied parallel and transverse electric field strengths
indicate that with increasing parallel electric field intensity, the binding energy values are increased, especially
in the higher parallel field strength, whereas the BE values for the applied transverse electric field
show a significant reverse trend. Results of this study indicate that with increasing parallel electric
field intensity the pristine AlNNT can be used as CO storage and the parallel electric field
effect is an ideal method for adsorption, storage, and fabrication of CO sensors.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3518

Baei, M.T.

Torabi, P.

Electronic Sumy State University Institutional Repository

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE NANOMATERIALS: APPLICATIONS AND PROPERTIES Vol. 1 No 3, 03PCSI18(2pp) (2012)   2304-1862/2012/1(3)03PCSI18(2) 03PCSI18-1  2012 Sumy State University Electric Field Effect in CO Adsorption on the (6,0) Zigzag Single-walled Aluminum Nitride Nanotube: an Ideal Method for CO Adsorption  P. Torbi1,*, Mohammad T. Baei2  1 Department of Chemistry, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran 2 Department of Chemistry, Azadshahr Branch, Islamic Azad University, Azadshahr, Golestan, Iran  (Received 28 June 2012; published online 07 August 2012)  The behavior of the monoxide carbon (CO) adsorbed on the external surface of H-capped (6,0) zigzag single-walled aluminum nitride nanotube was studied under the parallel and transverse electric fields with strengths 0-140 × 10-4 a.u. by using density functional calculations. Geometry optimizations were car-ried out at the B3LYP/6-31G* level of theory using the Gaussian 03 suite of programs. The binding ener-gies obtained from these calculations at different applied parallel and transverse electric field strengths indicate that with increasing parallel electric field intensity, the binding energy values are increased, espe-cially in the higher parallel field strength, whereas the BE values for the applied transverse electric field show a significant reverse trend. Results of this study indicate that with increasing parallel elec-tric field intensity the pristine AlNNT can be used as CO storage and the parallel electric field effect is an ideal method for adsorption, storage, and fabrication of CO sensors. Keywords: Aluminum nitride nanotube, Adsorption, Dipole moment.    PACS numbers: 68.43. – h, 61.46.Fg                                                             * Ptorabi87@yahoo.com 1. INTRODUCTION  Tuning the electronic structures of the semiconducting AlNNTs for specific application is evident important in building specific electronic and mechanical devices.  Improving the sensing performance of the pristine nanotubes and nano sheets by manipulating their structure is too expensive; therefore, finding high sensitive pristine nanotubes is of scientific interest. Electric field effect is one of the best techniques for improvement of the electronic structure properties of nanotubes and adsorption of gaseous molecules on the tubes surface. In recent years, several studies have been put in the computational calculation of the field effects on the electronic and structural properties of nanotubes [1-3]. However, to our knowledge, no experiments and theoretical investigation have been reported on adsorption of CO on AlNNT surfaces under electric field effect. Therefore, the understanding of the chemisorptions of CO on AlNNT surfaces under electric field effect is important for CO storage and fabrication of CO sensors.  2. COMPUTATIONAL METHODS  The hydrogenated models of the pristine (6,0) zig-zag AlNNT and the CO- attached (6,0)AlNNT models consist of 72 atoms with formulas  Al30N30H16 (pris-tine), and 74 atoms  with formula of Al30N30H16CO . In the first step, all the atomic geometrical parameters of the structures were allowed to relax in the optimization at the DFT level of B3LYP exchange functional and 6-31G* standard basis set. The binding energy (BE) of the CO- attached (6,0)AlNNT complex was calculated as follows:   BE = [ECO-AlNNT] – [EAlNNT + ECO] (1) Where ECO-AlNNT was obtained from optimization of the CO- attached (6,0)AlNNT model, EAlNNT and ECO are the energy of the optimized AlNNT and CO structures. A negative BE denotes exothermic substitute.  Then, we studied influence of the static external electric field on adsorption and structural and electronic properties of the complex, separately applied at the positive X- and positive Y-directions, which is parallel and perpendicular to X and Y plane. The numerical values of static electric field strengths in X and Y directions on the CO- attached (6,0)AlNNT  complex are 35 × 10-4, 70 × 10-4, 100 × 10-4,  and 140 × 10-4 a.u. (1 a.u. = 5.14224 × 1011 V/m) [4]. All the calculations were carried out by using the Gaussian 03 suite of programs [5].  3. RESULT AND DISCUSION  For the adsorption of CO on the AlNNT, we considered four possible sites (i.e., the center site, above the hexa-gon, the Al and N sites above the aluminum and nitro-gen atoms, and the Z site above the zigzag and axial Al–N bond) with two orientation (C-down and O-down) as described in Fig. 1a, b. The notation C-down and O-down denotes a CO molecule oriented perpendicular to the surface via C and O atoms. We limited our analysis to the interaction of CO with the nanotube, outer walls. In the first step, the structures were allowed to relax by all atomic geometrical parameters in the optimiza-tion at the DFT level of B3LYP exchange-functional and 6-31G* standard basis set. After structural optimi-zations, it is found that CO adsorption on center, nitro-gen, and Z sites are energetically unstable and are col-lapsed to the aluminum site, which is energetically favorable. The binding energies (BEs) of CO (C-down and O-down) with the equilibrium distances (RAl-C and RAl-O) at the aluminum site on the zigzag configuration  P. TORABI, M. T. BAEI PROC. NAP 1, 03PCSI18 (2012)   03PCSI18-2 of (6,0) AlNNT are summarized in Fig. 1a, b. For the states, the BEs are attractive, which characterizes a chemisorption process, also, the calculated BE for CO in C-down (BE = -0.42 eV) is more than that in O-down (BE = -0.12 eV). Therefore, we limited static external electric field effect to the interaction of CO at the alu-minum site with C-down.    Fig. 2 – (a) and (b) Two-dimensional (2D) views and adsorption configurations of CO (C-down and O-down) on (6,0) zigzag AlNNT (c) 2D views of CO- attached (6,0)AlNNT complex, and (d) Three-dimensional (3D) views of the CO- attached (6,0)AlNNT complex  The total energy (ET) and BEs for the optimized structure of CO-attached (6,0) AlNNT complex at the aluminum site with C-down at various applied parallel and transverse electric field strengths is calculated. The BEs obtained from these calculations at different applied parallel electric field strengths with respect to the corresponding values at zero fields (EX = EY = 0) indicate that with increasing parallel electric field intensity, the ET and BE values are increased. The BE values for the applied transverse electric field show a significant reverse trend, increasing with increasing transverse electric field intensity. The BE value for the applied parallel electric field is gradually increased from -0.42 eV at the zero field strength (EX = 0) to – 0.80 eV at the field strength of 140 × 10-4 a.u (EX = 140), whereas the BE value for the applied transverse electric field is gradually decreased from -0.42 eV at the zero field strength (EY=0) to -0.40 eV at the field strength of 140 × 10-4 a.u (EY=140). Therefore, the BE of the CO for the applied parallel electric field (EX) from zero field strength to 140 × 10-4 a.u. increases by 90 %, and the BE of the CO for the applied transverse electric field (EY) from zero field strength to 140 × 10-4 a.u. decreases by 5 % . Also, the values of RAl-C the complex decreased slightly by external electric field. The calculated BEs of the complex indicated that CO can significantly be adsorbed on the AlNNT by external parallel electric field (EX) and the CO adsorption on the AlNNT is sensitive to the strength of the electric field applied to the AlNNT surface. Therefore, with this method, pristine AlNNT can be used as CO storage and increase of parallel electric field effect (EX) is an ideal method for CO adsorption on AlNNTs and fabrication of CO sensors.   4. CONCLUSION  We studied the adsorption of CO molecule on (6,0) zigzag AlNNT at different applied parallel and trans-verse electric field strengths  by means of density func-tional theory (DFT) calculations. We compared all the BE of CO interacting with all possible sites of adsorp-tion on nanotube walls in several structural configura-tions. The calculated BE for CO in C-down configura-tion is higher than that in O-down and aluminum site is the most stable configuration. The BEs obtained from these calculations at different applied parallel electric field strengths with respect to the correspond-ing values at zero fields indicate that with increasing parallel electric field intensity, the ET and BE values are increased and CO can be absorbed significantly on the AlNNT, especially to the higher parallel field strength, whereas the BE values for the applied trans-verse electric field show a significant reverse trend..  AKNOWLEDGEMENTS  This work was financially supported by Islamic Azad University, Mahshahr Branch.   REFERENCES  1. K. H. Khoo, M. S. C. Mazzoni, S. G. Louie, Phys. Rev. B 69, 201401(R) (2004).  2. G. Y. Guo, S. Ishibashi, T. Tamura, K. Terakura, Phys. Rev. B 75, 245403(2007). 3. C. Attaccalite, L. Wirtz, A. Marini, A. Rubio, phys. status solidi B 244, 4288 (2007).  4. H. Sabzyan, D. Farmanzadeh, J. Comp. Chem. 28, 923 (2007). 5. M.J. Frisch et al. Gaussian 03, revision B03, Gaussian Inc (Pittsburgh, PA, 2003).    

Electric Field Effect in CO Adsorption on the (6,0) Zigzag Single-walled Aluminum Nitride Nanotube: an Ideal Method for CO Adsorption

SocioEconomic Challenges Journal (Sumy State University)

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE NANOMATERIALS: APPLICATIONS AND PROPERTIES 
Vol. 1 No 3, 03PCSI18(2pp) (2012) 
 
 
2304-1862/2012/1(3)03PCSI18(2) 03PCSI18-1  2012 Sumy State University 
Electric Field Effect in CO Adsorption on the (6,0) Zigzag Single-walled Aluminum Nitride 
Nanotube: an Ideal Method for CO Adsorption 
 
P. Torbi1,*, Mohammad T. Baei2 
 
1 Department of Chemistry, Mahshahr Branch, Islamic Azad University, Mahshahr, Iran 
2 Department of Chemistry, Azadshahr Branch, Islamic Azad University, Azadshahr, Golestan, Iran 
 
(Received 28 June 2012; published online 07 August 2012) 
 
The behavior of the monoxide carbon (CO) adsorbed on the external surface of H-capped (6,0) zigzag 
single-walled aluminum nitride nanotube was studied under the parallel and transverse electric fields 
with strengths 0-140 × 10-4 a.u. by using density functional calculations. Geometry optimizations were car-
ried out at the B3LYP/6-31G* level of theory using the Gaussian 03 suite of programs. The binding ener-
gies obtained from these calculations at different applied parallel and transverse electric field strengths 
indicate that with increasing parallel electric field intensity, the binding energy values are increased, espe-
cially in the higher parallel field strength, whereas the BE values for the applied transverse electric field 
show a significant reverse trend. Results of this study indicate that with increasing parallel elec-
tric field intensity the pristine AlNNT can be used as CO storage and the parallel electric field 
effect is an ideal method for adsorption, storage, and fabrication of CO sensors. 
Keywords: Aluminum nitride nanotube, Adsorption, Dipole moment. 
 
  PACS numbers: 68.43. – h, 61.46.Fg 
 
 
                                                          
* Ptorabi87@yahoo.com 
1. INTRODUCTION 
 
Tuning the electronic structures of the 
semiconducting AlNNTs for specific application is 
evident important in building specific electronic and 
mechanical devices.  Improving the sensing performance 
of the pristine nanotubes and nano sheets by 
manipulating their structure is too expensive; therefore, 
finding high sensitive pristine nanotubes is of scientific 
interest. Electric field effect is one of the best techniques 
for improvement of the electronic structure properties of 
nanotubes and adsorption of gaseous molecules on the 
tubes surface. In recent years, several studies have been 
put in the computational calculation of the field effects 
on the electronic and structural properties of nanotubes 
[1-3]. However, to our knowledge, no experiments and 
theoretical investigation have been reported on 
adsorption of CO on AlNNT surfaces under electric field 
effect. Therefore, the understanding of the 
chemisorptions of CO on AlNNT surfaces under electric 
field effect is important for CO storage and fabrication of 
CO sensors. 
 
2. COMPUTATIONAL METHODS 
 
The hydrogenated models of the pristine (6,0) zig-
zag AlNNT and the CO- attached (6,0)AlNNT models 
consist of 72 atoms with formulas  Al30N30H16 (pris-
tine), and 74 atoms  with formula of Al30N30H16CO . In 
the first step, all the atomic geometrical parameters of 
the structures were allowed to relax in the optimization 
at the DFT level of B3LYP exchange functional and 6-
31G* standard basis set. The binding energy (BE) of 
the CO- attached (6,0)AlNNT complex was calculated 
as follows:  
 BE = [ECO-AlNNT] – [EAlNNT + ECO] (1) 
Where ECO-AlNNT was obtained from optimization of 
the CO- attached (6,0)AlNNT model, EAlNNT and ECO 
are the energy of the optimized AlNNT and CO 
structures. A negative BE denotes exothermic 
substitute.  Then, we studied influence of the static 
external electric field on adsorption and structural and 
electronic properties of the complex, separately applied 
at the positive X- and positive Y-directions, which is 
parallel and perpendicular to X and Y plane. The 
numerical values of static electric field strengths in X 
and Y directions on the CO- attached (6,0)AlNNT  
complex are 35 × 10-4, 70 × 10-4, 100 × 10-4,  and 140 × 
10-4 a.u. (1 a.u. = 5.14224 × 1011 V/m) [4]. All the 
calculations were carried out by using the Gaussian 03 
suite of programs [5]. 
 
3. RESULT AND DISCUSION 
 
For the adsorption of CO on the AlNNT, we considered 
four possible sites (i.e., the center site, above the hexa-
gon, the Al and N sites above the aluminum and nitro-
gen atoms, and the Z site above the zigzag and axial 
Al–N bond) with two orientation (C-down and O-down) 
as described in Fig. 1a, b. The notation C-down and O-
down denotes a CO molecule oriented perpendicular to 
the surface via C and O atoms. We limited our analysis 
to the interaction of CO with the nanotube, outer walls. 
In the first step, the structures were allowed to relax 
by all atomic geometrical parameters in the optimiza-
tion at the DFT level of B3LYP exchange-functional 
and 6-31G* standard basis set. After structural optimi-
zations, it is found that CO adsorption on center, nitro-
gen, and Z sites are energetically unstable and are col-
lapsed to the aluminum site, which is energetically 
favorable. The binding energies (BEs) of CO (C-down 
and O-down) with the equilibrium distances (RAl-C and 
RAl-O) at the aluminum site on the zigzag configuration 
 P. TORABI, M. T. BAEI PROC. NAP 1, 03PCSI18 (2012) 
 
 
03PCSI18-2 
of (6,0) AlNNT are summarized in Fig. 1a, b. For the 
states, the BEs are attractive, which characterizes a 
chemisorption process, also, the calculated BE for CO 
in C-down (BE = -0.42 eV) is more than that in O-down 
(BE = -0.12 eV). Therefore, we limited static external 
electric field effect to the interaction of CO at the alu-
minum site with C-down.  
 
 
Fig. 2 – (a) and (b) Two-dimensional (2D) views and 
adsorption configurations of CO (C-down and O-down) on (6,0) 
zigzag AlNNT (c) 2D views of CO- attached (6,0)AlNNT 
complex, and (d) Three-dimensional (3D) views of the CO- 
attached (6,0)AlNNT complex 
 
The total energy (ET) and BEs for the optimized 
structure of CO-attached (6,0) AlNNT complex at the 
aluminum site with C-down at various applied parallel 
and transverse electric field strengths is calculated. 
The BEs obtained from these calculations at different 
applied parallel electric field strengths with respect to 
the corresponding values at zero fields (EX = EY = 0) 
indicate that with increasing parallel electric field 
intensity, the ET and BE values are increased. The BE 
values for the applied transverse electric field show a 
significant reverse trend, increasing with increasing 
transverse electric field intensity. The BE value for the 
applied parallel electric field is gradually increased from 
-0.42 eV at the zero field strength (EX = 0) to – 0.80 eV at 
the field strength of 140 × 10-4 a.u (EX = 140), whereas 
the BE value for the applied transverse electric field is 
gradually decreased from -0.42 eV at the zero field 
strength (EY=0) to -0.40 eV at the field strength of 140 
× 10-4 a.u (EY=140). Therefore, the BE of the CO for the 
applied parallel electric field (EX) from zero field 
strength to 140 × 10-4 a.u. increases by 90 %, and the 
BE of the CO for the applied transverse electric field 
(EY) from zero field strength to 140 × 10-4 a.u. decreases 
by 5 % . Also, the values of RAl-C the complex decreased 
slightly by external electric field. The calculated BEs of 
the complex indicated that CO can significantly be 
adsorbed on the AlNNT by external parallel electric 
field (EX) and the CO adsorption on the AlNNT is 
sensitive to the strength of the electric field applied to 
the AlNNT surface. Therefore, with this method, 
pristine AlNNT can be used as CO storage and increase 
of parallel electric field effect (EX) is an ideal method 
for CO adsorption on AlNNTs and fabrication of CO 
sensors.  
 
4. CONCLUSION 
 
We studied the adsorption of CO molecule on (6,0) 
zigzag AlNNT at different applied parallel and trans-
verse electric field strengths  by means of density func-
tional theory (DFT) calculations. We compared all the 
BE of CO interacting with all possible sites of adsorp-
tion on nanotube walls in several structural configura-
tions. The calculated BE for CO in C-down configura-
tion is higher than that in O-down and aluminum site 
is the most stable configuration. The BEs obtained 
from these calculations at different applied parallel 
electric field strengths with respect to the correspond-
ing values at zero fields indicate that with increasing 
parallel electric field intensity, the ET and BE values 
are increased and CO can be absorbed significantly on 
the AlNNT, especially to the higher parallel field 
strength, whereas the BE values for the applied trans-
verse electric field show a significant reverse trend..  
AKNOWLEDGEMENTS 
 
This work was financially supported by Islamic Azad 
University, Mahshahr Branch. 
 
 
REFERENCES 
 
1. K. H. Khoo, M. S. C. Mazzoni, S. G. Louie, Phys. Rev. B 69, 
201401(R) (2004).  
2. G. Y. Guo, S. Ishibashi, T. Tamura, K. Terakura, Phys. 
Rev. B 75, 245403(2007). 
3. C. Attaccalite, L. Wirtz, A. Marini, A. Rubio, phys. status 
solidi B 244, 4288 (2007).  
4. H. Sabzyan, D. Farmanzadeh, J. Comp. Chem. 28, 923 
(2007). 
5. M.J. Frisch et al. Gaussian 03, revision B03, Gaussian Inc 
(Pittsburgh, PA, 2003). 
 
 
 


English

https://essuir.sumdu.edu.ua/bitstream/123456789/35182/1/princon_2012_1_3_63.pdf

Electric Field Effect in CO Adsorption on the (6,0) Zigzag Single-walled Aluminum Nitride Nanotube: an Ideal Method for CO Adsorption

Abstract

Similar works

Full text

Available Versions

Electronic Sumy State University Institutional Repository

SocioEconomic Challenges Journal (Sumy State University)