DFT investigation on CO sensing characteristics of hexagonal and orthorhombic WO3 nanostructures

Nagarajan, V.; Chandiramouli, R.

doi:10.1016/j.spmi.2014.11.027

Cited by 36 publications

(11 citation statements)

References 49 publications

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“…However, compared with the experimental reports, theoretical publications in regard to CO sensing with WO 3 gas sensor are lacking so far. Most present theoretical works mainly focus on the adsorption behavior of CO at WO 3 surfaces [ 21 ], while few studies refer to the CO oxidation on the WO 3 surface for sensing. Oison [ 22 ] et al investigated the CO adsorption condition on WO 3 film with and without redox reaction via ab initio calculations.…”

Section: Introductionmentioning

confidence: 99%

Insight into the Mechanism of CO Oxidation on WO3(001) Surfaces for Gas Sensing: A DFT Study

Jiang

Zhou

Zhang

2017

Sensors

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The mechanism of CO oxidation on the WO3(001) surface for gas sensing performance has been systematically investigated by means of first principles density functional theory (DFT) calculations. Our results show that the oxidation of CO molecule on the perfect WO3(001) surface induces the formation of surface oxygen vacancies, which results in an increase of the surface conductance. This defective WO3(001) surface can be re-oxidized by the O2 molecules in the atmosphere. During this step, the active O2− species is generated, accompanied with the obvious charge transfer from the surface to O2 molecule, and correspondingly, the surface conductivity is reduced. The O2− species tends to take part in the subsequent reaction with the CO molecule, and after releasing CO2 molecule, the perfect WO3(001) surface is finally reproduced. The activation energy barriers and the reaction energies associated with above surface reactions are determined, and from the kinetics viewpoint, the oxidation of CO molecule on the perfect WO3(001) surface is the rate-limiting step with an activation barrier of about 0.91 eV.

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Section: Introductionmentioning

confidence: 99%

Insight into the Mechanism of CO Oxidation on WO3(001) Surfaces for Gas Sensing: A DFT Study

Jiang

Zhou

Zhang

2017

Sensors

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“… 58 − 60 Additionally, LanL2DZ was used to provide a more consistent output with pseudopotential approximation in the periodic system. 61 , 62 The modeled graphene surface consists of 24 carbon atoms with 12 terminal hydrogen atoms used to prevent the dangling of graphene structural bonds. The frequency calculations along with geometry optimizations were based on the standard hybrid exchange–correlation function of Becke’s three parameters of Lee, Yang, and Parr (B3LYP).…”

Section: Computational Detailsmentioning

confidence: 99%

Theoretical Study of CO Adsorption Interactions with Cr-Doped Tungsten Oxide/Graphene Composites for Gas Sensor Application

et al. 2021

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The present study explores the CO adsorption properties with graphene, tungsten oxide/graphene composite, and Cr-doped tungsten oxide/graphene composite using density functional theory (DFT) calculations. The results of the study reveal the Cr-doped tungsten oxide/graphene composites, g-CrW n –1 O 3 n ( n = 2 to 4), to have a lowered highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) energy gap, high surface reactivity, and a strong cluster–graphene binding energy, hence exhibiting a strong adsorption interaction with CO. The CO adsorption interaction shows physisorption properties by having a greater tendency for Mulliken and natural bond orbital (NBO) charge transfer supported by a strong physisorption interaction toward the g-CrW n –1 O 3 n ( n = 2 to 4) composite with HOMO–LUMO energy gaps of −0.638, −0.486, and −0.327 eV, respectively. The calculated photoelectron spectroscopy (PES) and infrared spectra combined with the visualized electrostatic potential and contour line confirm the population density of the physisorption interaction. The calculated results show that the g-CrW n –1 O 3 n composite achieves a greater sensing ability by possessing the highest sensitivity, adsorption, and desorption characteristics for n = 2 (g-CrWO 6 composite). In conclusion, Cr-doped tungsten oxide/graphene has high sensitivity toward CO gas.

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“…The transfer of electrons between Cl 2 molecule and α-Cr 2 O 3 material can be analysed by Mulliken population analysis (Q). [26][27][28][29][30][31][32][33][34][35] The negative charge of Mulliken population refers that the electrons are transferred from α-Cr 2 O 3 material to Cl 2 gas molecules and in contrast, the positive charge of Q depicts the electrons transferred from Cl 2 gas molecules to α-Cr 2 O 3 material. The Mulliken population values of pristine α-Cr 2 O 3 nanostructure for positions A and B are found to be 0.002 and −0.25 e, respectively.…”

Section: Adsorption Characteristics Of CL 2 On α-Cr 2 O 3 Nanostructuresmentioning

confidence: 99%

A first-principles study of chlorine adsorption characteristics on α-Cr2O3 nanostructures

Nagarajan

Chandiramouli

2015

J Chem Sci

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The structural stability, electronic and adsorption properties of chlorine on pristine, Zn, W and Nsubstituted α-Cr 2 O 3 nanostructures are successfully optimized and simulated with the help of density functional theory utilizing B3LYP/ LanL2DZ basis set. The structural stability of α-Cr 2 O 3 nanostructures are discussed in terms of formation energy. The electronic properties of pristine, Zn, W and N-substituted α-Cr 2 O 3 nanostructures are described with HOMO-LUMO gap, ionization potential and electron affinity. Dipole moment and point symmetry group of pristine, Zn, W and N-substituted α-Cr 2 O 3 nanostructures are reported. The adsorption characteristics of Cl 2 on α-Cr 2 O 3 materials are investigated and the prominent adsorption sites of Cl 2 on α-Cr 2 O 3 nanostructures are identified. The important parameters such as adsorbed energy, energy gap, average energy gap variation and Mulliken population analysis are used to find the favourable adsorption site of Cl 2 on α-Cr 2 O 3 base material. The substitution of impurities such as Zn, W and N in α-Cr 2 O 3 nanostructures enhances the Cl 2 adsorption characteristics in the mixed gas environment.

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DFT investigation on CO sensing characteristics of hexagonal and orthorhombic WO3 nanostructures

Cited by 36 publications

References 49 publications

Insight into the Mechanism of CO Oxidation on WO3(001) Surfaces for Gas Sensing: A DFT Study

Insight into the Mechanism of CO Oxidation on WO3(001) Surfaces for Gas Sensing: A DFT Study

Theoretical Study of CO Adsorption Interactions with Cr-Doped Tungsten Oxide/Graphene Composites for Gas Sensor Application

A first-principles study of chlorine adsorption characteristics on α-Cr2O3 nanostructures

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