Study on adsorption of CO and CO2 by graphene gas sensor

2021 ◽  
pp. 2150154
Author(s):  
Wenchao Tian ◽  
Jiahao Niu ◽  
Wenhua Li ◽  
Xiaohan Liu
Keyword(s):  
Gas Sensors ◽  
Active Sites ◽  
Density Functional ◽  
Gas Adsorption ◽  
Experimental Studies ◽  
Detection Accuracy ◽  
Functional Theory ◽  
Vacancy Defects ◽  
Adsorption Of Co ◽  
Detection Characteristics

The two-dimensional (2D) plane of graphene has many active sites for gas adsorption. It has broad application prospects in the field of MEMS gas sensors. At present, there are many experimental studies on graphene gas sensors, but it is difficult to accurately control various influencing factors in the experiments. Therefore, this paper applies the first principle based on density functional theory to study the adsorption and detection characteristics of graphene on CO and CO2. The first-principles analysis method was used to study the adsorption characteristics and sensitivity of graphene. The results show that the inductive graphene has a sensitivity of 1.55% and 0.77% for CO and CO2, respectively. The Stone–Wales defects and multi-vacancy defects have greatly improved the sensitivity of graphene to CO, which is 35.25% and 4.14%, respectively. Introduction of defects increases the sensitivity of detection of CO and CO2, but also improves the selective gas detection material of these two gases. Thus, the control and selectively introducing defects may improve the detection accuracy of the graphene CO and CO2.

A model of FeN-decorated BeO layer particle for CO gas adsorption

2021 ◽  
pp. 1-8
Author(s):  
Kosar Zarifi ◽  
Farnaz Rezaei ◽  
Seyed Mehdi Seyed Alizadeh
Keyword(s):  
Density Functional ◽  
Gas Adsorption ◽  
Human Life ◽  
Beryllium Oxide ◽  
Functional Theory ◽  
Nitrogen Doped ◽  
Health Quality ◽  
Adsorption Of Co ◽  
Model Formation ◽  
Co Gas

Carbon monoxide (CO) is known as a deathful gas produced by burning of hydrocarbons in a lack of enough oxygen, in which breathing CO leads to serious issues on human life health quality. Therefore, adsorption of CO gas is an essential task for diagnosis or removal of this dreadful gas in environment. To do this, a HEME-like model of iron-nitrogen-doped beryllium oxide (FeNBeO) monolayer was investigated for adsorbing CO gas by performing density functional theory (DFT) calculations. Two models were obtained for this process, in which relaxation of CO with C-head or O-head towards Fe region of monolayer. The results indicated that the formation of FeNBeO-CO model could be achieved more favorable than the formation of FeNBeO-OC model. The obtained optimized geometers and energies all approved this achievement for favorability of FeNBeO-CO model formation. Moreover, molecular orbital based electronic features indicated variations of such features for the models upon adsorption of CO substance, in which the models could be detectable in a sensor function for the existence of CO gas in the environment. As a consequence, the investigated FeNBeO monolayer could be proposed useful for adsorption of CO gas at least for the CO deathful gas diagnosis purposes.

Interaction of CO with Pd-Doped α-Fe2O3 (001) in the CLC System: A Density Functional Analysis

2011 ◽  
Vol 403-408 ◽  
pp. 2285-2288 ◽  
Author(s):  
Wu Qin ◽  
Qiu Luan Chen ◽  
Tie Cheng Wang ◽  
Ning Wang ◽  
Wen Yan Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Functional Analysis ◽  
Surface Layer ◽  
Active Sites ◽  
Density Functional ◽  
Theoretical Interpretation ◽  
Functional Theory ◽  
System A ◽  
Adsorption Of Co ◽  
The Ideal

The present work is devoted to the theoretical interpretation of interaction of CO molecule with Pd-doped α-Fe2O3(001) using density functional theory (DFT). Two doping types were taken into account, which either a pair of Fe atoms of α-Fe2O3(001) surface was replaced by Pd or a pair of Pd atoms embedded into the vacancy between surface layer and sub-surface layer of α-Fe2O3(001). Three different active sites of the α-Fe2O3(001) surface and the Pd-doped α-Fe2O3(001) surface were considered for the interaction between CO and these surfaces. We found that the binding energy of CO on Pd-doped α-Fe2O3(001) surface was much more than that of the clean α-Fe2O3(001) surface. Results indicated metallic atoms are a Subscript text ctive site for adsorption of CO molecule, and the S(001) while interaction between CO molecule and surface doped by replacing Fe atom with Pd atom, stronger interaction happen between CO molecule and Pd embedded-doped α-Fe2O3(001) surface than that between CO molecule and the ideal surface, leading to the formation of CO2precursor species.

scholarly journals Individual Gas Molecules Detection Using Zinc Oxide–Graphene Hybrid Nanosensor: A DFT Study

2018 ◽  
Vol 4 (3) ◽  
pp. 44 ◽  
Author(s):  
Ingrid Torres ◽  
Sadegh Mehdi Aghaei ◽  
Amin Rabiei Baboukani ◽  
Chunlei Wang ◽  
Shekhar Bhansali
Keyword(s):  
Zinc Oxide ◽  
Active Sites ◽  
Density Functional ◽  
Gas Adsorption ◽  
Pristine Graphene ◽  
Functional Theory ◽  
Gas Molecules ◽  
Low Sensitivity ◽  
Substantial Change ◽  
Large Charge

Surface modification is a reliable method to enhance the sensing properties of pristine graphene by increasing active sites on its surface. Herein, we investigate the interactions of the gas molecules such as NH3, NO, NO2, H2O, and H2S with a zinc oxide (ZnO)–graphene hybrid nanostructure. Using first-principles density functional theory (DFT), the effects of gas adsorption on the electronic and transport properties of the sensor are examined. The computations show that the sensitivity of the pristine graphene to the above gas molecules is considerably improved after hybridization with zinc oxide. The sensor shows low sensitivity to the NH3 and H2O because of the hydrogen-bonding interactions between the gas molecules and the sensor. Owing to observable alterations in the conductance, large charge transfer, and high adsorption energy; the sensor possesses extraordinary potential for NO and NO2 detection. Interestingly, the H2S gas is totally dissociated through the adsorption process, and a large number of electrons are transferred from the molecule to the sensor, resulting in a substantial change in the conductance of the sensor. As a result, the ZnO–graphene nanosensor might be an auspicious catalyst for H2S dissociation. Our findings open new doors for environment and energy research applications at the nanoscale.

Molecular Investigations of the Newly Synthesized Azomethines as Antioxidants: Theoretical and Experimental Studies

2019 ◽  
Vol 19 (6) ◽  
pp. 419-433 ◽  
Author(s):  
Siyamak Shahab ◽  
Masoome Sheikhi ◽  
Liudmila Filippovich ◽  
Evgenij Dikusar ◽  
Anhelina Pazniak ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Experimental Studies ◽  
Antioxidant Property ◽  
Nbo Analysis ◽  
Antioxidant Potential ◽  
Functional Theory ◽  
Homo And Lumo ◽  
Intramolecular Hydrogen ◽  
Activity Mechanism

: In this study, the antioxidant property of new synthesized azomethins has been investigated as theoretical and experimental. Methods and Results: Density functional theory (DFT) was employed to investigate the Bond Dissociation Enthalpy (BDE), Mulliken Charges, NBO analysis, Ionization Potential (IP), Electron Affinities (EA), HOMO and LUMO energies, Hardness (η), Softness (S), Electronegativity (µ), Electrophilic Index (ω), Electron Donating Power (ω-), Electron Accepting Power (ω+) and Energy Gap (Eg) in order to deduce scavenging action of the two new synthesized azomethines (FD-1 and FD-2). Spin density calculations and NBO analysis were also carried out to understand the antioxidant activity mechanism. Comparison of BDE of FD-1 and FD-2 indicate the weal antioxidant potential of these structures. Conclusion: FD-1 and FD-2 have very high antioxidant potential due to the planarity and formation of intramolecular hydrogen bonds.

scholarly journals Study on the adsorption selection of CH$$_4$$ on CuO (110) versus (111) surfaces: a density functional theory study

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Long Lin ◽  
Linwei Yao ◽  
Shaofei Li ◽  
Zhengguang Shi ◽  
Kun Xie ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Adsorption Capacity ◽  
Active Sites ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Density Functional Theory Calculations ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Strong Adsorption ◽  
Selection Of

AbstractFinding the active sites of suitable metal oxides is a key prerequisite for detecting CH$$_4$$ 4 . The purpose of the paper is to investigate the adsorption of CH$$_4$$ 4 on intrinsic and oxygen-vacancies CuO (111) and (110) surfaces using density functional theory calculations. The results show that CH$$_4$$ 4 has a strong adsorption energy of −0.370 to 0.391 eV at all site on the CuO (110) surface. The adsorption capacity of CH$$_4$$ 4 on CuO (111) surface is weak, ranging from −0.156 to −0.325 eV. In the surface containing oxygen vacancies, the adsorption capacity of CuO surface to CH$$_4$$ 4 is significantly stronger than that of intrinsic CuO surface. The results indicate that CuO (110) has strong adsorption and charge transfer capacity for CH$$_4$$ 4 , which may provide experimental guidance.

scholarly journals Density Functional Theory and Molecular Docking Investigations of the Chemical and Antibacterial Activities for 1-(4-Hydroxyphenyl)-3-phenylprop-2-en-1-one

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3631
Author(s):  
Ahmed M. Deghady ◽  
Rageh K. Hussein ◽  
Abdulrahman G. Alhamzani ◽  
Abeer Mera
Keyword(s):  
Density Functional Theory ◽  
Antibacterial Activity ◽  
Molecular Docking ◽  
Carbonyl Group ◽  
Active Sites ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Basis Set ◽  
Molecular Docking Study ◽  
Functional Theory

The present investigation informs a descriptive study of 1-(4-Hydroxyphenyl) -3-phenylprop-2-en-1-one compound, by using density functional theory at B3LYP method with 6-311G** basis set. The oxygen atoms and π-system revealed a high chemical reactivity for the title compound as electron donor spots and active sites for an electrophilic attack. Quantum chemical parameters such as hardness (η), softness (S), electronegativity (χ), and electrophilicity (ω) were yielded as descriptors for the molecule’s chemical behavior. The optimized molecular structure was obtained, and the experimental data were matched with geometrical analysis values describing the molecule’s stable structure. The computed FT-IR and Raman vibrational frequencies were in good agreement with those observed experimentally. In a molecular docking study, the inhibitory potential of the studied molecule was evaluated against the penicillin-binding proteins of Staphylococcus aureus bacteria. The carbonyl group in the molecule was shown to play a significant role in antibacterial activity, four bonds were formed by the carbonyl group with the key protein of the bacteria (three favorable hydrogen bonds plus one van der Waals bond) out of six interactions. The strong antibacterial activity was also indicated by the calculated high binding energy (−7.40 kcal/mol).

The structure and activity of potassium supported on SBA-15 molecular sieve: Density functional theory study

2014 ◽  
Vol 13 (01) ◽  
pp. 1350076 ◽  
Author(s):  
Bing Liu ◽  
Daxi Wang ◽  
Zhongxue Wang ◽  
Zhen Zhao ◽  
Yu Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Lewis Acid ◽  
Molecular Sieve ◽  
Active Sites ◽  
Density Functional ◽  
Structural Model ◽  
Vibrational Frequencies ◽  
Oxygen Molecule ◽  
Lewis Base ◽  
Functional Theory

The geometries, vibrational frequencies, electronic properties and reactivity of potassium supported on SBA-15 have been theoretically investigated by the density functional theory (DFT) method. The structural model of the potassium supported on SBA-15 was constructed based on our previous work [Wang ZX, Wang DX, Zhao Z, Chen Y, Lan J, A DFT study of the structural units in SBA-15 mesoporous molecular sieve, Comput. Theor. Chem.963, 403, 2011]. This paper is the extension of our previous work. The most favored location of potassium atom was obtained by the calculation of substitution energy. The calculated vibrational frequencies of K /SBA-15 are in good agreement with the experimental results. By analyzing the properties of electronic structure, we found that the O atom of Si - O (2)- K group acts as the Lewis base center and the K atom acts as the Lewis acid center. The reactivity of K /SBA-15 was investigated by calculating the activation of oxygen molecule. The oxygen molecule can be activated by K /SBA-15 with an energy barrier of 103.2 kJ/mol. In the final state, the activated oxygen atoms become new Lewis acid centers, which are predicted to act as the active sites in the catalytic reactions. This study provides a deep insight into the properties of supported potassium catalysts and offers fundamental information for further research.

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