Adsorption Properties of Metal Atom (Co, V, W, Zr)-Modified MoTe2 for CO, CH3CHO, and C6H6 Gases: A DFT Study

Abstract

This study investigates the adsorption characteristics of the pristine MoTe₂ monolayer and the metal atom (Co, V, W, Zr)-modified MoTe₂ monolayer on the hazardous gases CO, CH₃CHO, and C₆H₆ based on the density functional theory. The adsorption mechanism was studied from the perspectives of molecular density differences, band structures, molecular orbitals, and the density of states. Research analysis showed that the changes in conductivity caused by the adsorption of different gases on the substrate were significantly different, which can be used to prepare gas sensing materials with selective sensitivity for CO, CH₃CHO, and C₆H₆. This study lays a reliable theoretical foundation for the gas sensing analysis of toxic and hazardous gases using metal atom-modified MoTe₂ materials.

1. Introduction

Carbon monoxide (CO) is a colorless and odorless gas mainly derived from the incomplete combustion of fuels, such as gasoline, diesel, coal, etc. [1,2,3]. Carbon monoxide mainly comes from the exhaust and the incomplete combustion of an engine, especially when the combustion engine keeps turning on under a standby state. Long term exposure to CO may cause symptoms such as headache, dizziness, drowsiness, and even death [4,5,6]. Acetaldehyde (CH₃CHO) is an organic compound with a pungent odor. CH₃CHO is a common decomposition product of plastic parts, rubber parts, and other interior materials, while benzene (C₆H₆) often releases from materials such as adhesives and leather in cars [7,8,9,10,11]. It is worth noting that both CH₃CHO and C₆H₆ can cause serious damage to the human body at high concentrations. The harmful substances in the interior decoration materials release a lot of volatile organic pollutants [12,13,14]. In order to maintain human health and safety, it is necessary to detect and adsorb CO, CH₃CHO and C₆H₆ inside cars.

Since the emergence of graphene, two-dimensional materials have received attention from researchers in the field of gas sensing. Abbasi et al. found that the interaction between Al- or Si-atom-modified MoS₂ and gas molecules is stronger than that between the pristine MoS₂ and gas molecules, and can sensitively detect CO and NO in the environment [15]. In addition, they also constructed undoped and N-doped multi-component heterostructures, TiO₂/WSe₂ [16] and TiO₂/MoS₂ [17,18], to improve the gas adsorption of the material. Layered transition metal disulfides (TMDs), one of the materials with the highest degree of two-dimensional transformation, overcome the shortcomings of graphene’s zero bandgap characteristics and demonstrate enormous application potential. Each layer is composed of an alternating arrangement of transition metal atoms (Mo, Ti, W, etc.) and sulfur group element atoms (S, Se, Te, etc.), which are connected to each other through van der Waals force interactions [19,20,21]. This structure enables TMDs to have rich electronic structural states, such as topological insulating states, semi-conductive states, semi-metallic states, and superconducting states [22,23]. In addition, TMDs also have excellent optical [24,25,26] and structural properties [27,28], making them an ideal two-dimensional platform for studying various potential applications. Among the TMDs studied so far, MoTe₂ is considered a potential efficient sensing material due to its fast response [29]. It is worth mentioning that the homojunction efficiency of MoTe₂ reaches 10–50 times that of silicon, and electrons can move quickly [30,31]. According to the topological structure, MoTe₂ shows typical semiconductor characteristics [32,33,34]. A large amount of theoretical and experimental research has proven that the pristine MoTe₂ has a high sensing ability as an efficient gas detection device [35,36,37,38].

The surface modification of transition metals has been experimentally proven to be an effective way to improve the gas sensing properties of materials [39,40,41]. Wang et al. found that a MoTe₂ monolayer modified with Ni atoms significantly improved their adsorption capacity for SF₆ decomposition gases [42]. Lin et al. studied the adsorption behavior of Ag, Pd, and Rh atoms with different modification methods, and found that both the conductivity and chemical activity were improved after the metal atom modifications [43]. However, there is still limited research on the metal-element-modified MoTe₂. Han et al. used redox V-metal organic framework materials to adsorb NO₂ gas, and experimental results showed a high NO₂ absorption rate and excellent adsorption reversibility [44]. Zirconium based materials, such as zirconium-based metal organic frameworks (Zr-MOFs), are widely studied for gas adsorption and separation due to their high specific surface area and adjustable pore structure [45]. Related reports also indicate that W and Co atom modifications be used to prepare high-performance gas sensing materials, and the introduction of TM doping shows a significant enhancement of adsorption selectivity [46,47,48,49]. Therefore, this study explored the electronic properties of Co, V, W, and Zr-modified MoTe₂ monolayers (abbreviated as Metal-MoTe₂), and investigated its adsorption on the hazardous gases CO, CH₃CHO, and C₆H₆ through geometric optimization, charge density difference (CDD), band structure, the density of states, molecular orbitals, and desorption time analysis.

2. Results and Discussion

2.1. Structural Optimization of Gases, MoTe₂, and Metal-MoTe₂

Figure 1a,b show the optimized geometrical structure of the pristine MoTe₂ monolayer. The Mo and Te atoms were arranged alternately, with Mo atoms located in the middle of the monolayer, forming hexagonal rings. The bond length between the Mo atom and Te atom was 2.758 Å, and the angle formed by Te-Mo-Te was 80.348°. Among them, there were four typical adsorption sites on the MoTe₂ monolayer: T_H (middle of the hexagon), T_Te (above the Te atom), T_Mo (above the Mo atom), and T_B (above the bond connecting the Te and Mo atoms). In Figure 1c, the covalent bond length between the C and O atoms of the CO molecule was 1.142 Å, forming three bonds. The bond length of the CH₃CHO molecule is shown in Figure 1d, and the angle between O-C-H was 120.355°. The six carbon atoms of C₆H₆ formed a cyclic closed chain, with a C-C bond length of 1.399 Å. Each C atom was surrounded by an H atom, with a length of 1.091 Å. In addition, a comparison of the structural parameters (MoTe₂, CO, CH₃CHO, and C₆H₆) were obtained from our theoretical calculations and experimental tests from references, which are listed in Table S1.

The energy released when a MoTe₂ monolayer binds to metal atoms (Co, V, W, or Zr) is defined as the binding energy (E_b). The larger the absolute value of E_b, the more stable the structure is. In order to obtain the most stable configuration, the E_b and the nearest atomic adsorption distance were comprehensively considered. The optimal structures of the Metal-MoTe₂ monolayer are shown in Figure 2(a1–a4), where it can be seen that the Co (or V, W, Zr) atom located to the middle of the hexagon, indirectly being surrounded by the three Mo atoms. And, the edges of the hexagon where the metal atom was located underwent certain deformations compared to that before binding, indicating that corresponding chemical reactions occurred during the modification process. The E_b between the Co atom and MoTe₂ monolayer was −7.264 eV, indicating that the binding between an atom and the substrate was an exothermic process and very tight. At the same time, the Co atom, as an electron acceptor, obtained a charge of 0.338 e, and the large charge transfer and absolute adsorption energy indicated that intense chemical reactions occurred during the binding process.

The charge density difference (CDD) and band structure of the Metal-MoTe₂ monolayer were also carefully analyzed. Figure 2(b1–b4) show the CDD of the Metal-MoTe₂ monolayer. The blue color represents an increase in the charge density in the region, while the red color represents the opposite. The darker the color, the more the charge density in that area increased or decreased. From Figure 2(b1), it can be seen that the Co atom was tightly adhered to a deeper blue color and there was more electron aggregation in the bonding area, making the modification very stable. From Figure 2(b2), it can also be seen that strong charge transfer and redistribution occurred near the V atom, which was consistent with the phenomenon of a large E_b (−9.144 eV) and a distinct charge transfer (the MoTe₂ monolayer lost 0.230 e). The chemical reactions between the W/Zr atom and the substrate were relatively weak compared to the first two. The W atom and Zr atom obtained charges of 0.171 e and 0.216 e from the MoTe₂ monolayer with E_b values of −5.624 eV and −3.283 eV, respectively.

By observing the band structure shown in Figure 3 and comparing the relative positions and widths of the valence and conduction bands, the conductivity of the material was determined. As shown in Figure 3, the energy gap of the pristine MoTe₂ was 1.275 eV, while the energy gap decreased to varying degrees after modification with the four different atoms. The energy gaps arranged in order from small to large were Co-MoTe₂ < Zr-MoTe₂ < W-MoTe₂ < V-MoTe₂ < MoTe₂. The reduction in the energy gap made it easier for the electrons to jump between the valence and conduction bands, and atomic modification had a positive impact on the conductivity of the material.

2.2. Adsorption Analysis of CO, CH₃CHO, C₆H₆ on the Metal-MoTe₂

2.2.1. Structural Analysis

In order to directly perceive the adsorption behavior of the Metal-MoTe₂ monolayer on CO, CH₃CHO, and C₆H₆ gases, the related adsorption structures were plotted and the relevant parameters were summarized, as shown in Figure 4 and Table 1, respectively. In addition, the adsorption parameters of the pristine MoTe₂ monolayer for these three hazardous gases are also summarized, which were used to effectively compare and analyze the relevant parameters of the pristine system and the modification system. Adsorption energy (E_ads) refers to the interaction energy between the adsorbate and the adsorbent during the adsorption process. In this work, the magnitude of E_ads is defined as the sum of the energy of the gas molecules before adsorption and the energy of the substrate minus the energy of the substrate after adsorption of the gas. A negative E_ads indicates that this is an exothermic reaction, and that the adsorption process can occur spontaneously. Previous studies have shown that the addition of van der Waals interactions during adsorption increases the adsorption energy [16,50,51]. This article corrected for the influence of van der Waals interactions, but the calculation results showed that the adsorption energy was relatively large, so the influence of van der Waals interactions on the adsorption energy was relatively small. Overall analysis showed that when the Co-MoTe₂ adsorbed three gases, the bond length of Co-Mo changed very little, which may be related to the higher binding energy between the Co atom and the MoTe₂ monolayer. Compared with the pristine Co atom, the shortest atomic spacing for adsorbing CO gas after modification was decreased, while E_ads (−0.167 eV) decreased to about one-twentieth of the original adsorption energy, significantly reducing the adsorption energy. A smaller adsorption energy is beneficial for the desorption of small gas molecules, improving the reuse rate of the substrate. The adsorption energies of Co-MoTe₂ for CH₃CHO and C₆H₆ were −0.392 eV and −0.667 eV, respectively, with a slight increase in the shortest atomic spacing comparing to that before modification. In the V-MoTe₂ system, the adsorption distance of CO was 54.7% of the original, and the E_ads of CH₃CHO changed the most, decreasing to one-ninth of the original. The trend of changes in the CO adsorption parameters for the W-MoTe₂ system and the Zr-MoTe₂ system was the same. The adsorption distance of CO decreased to about half of the original, and the CO molecules were almost vertically downwards, with the closest distance between the C atom and the metal atom. The shortest atomic distance between W-MoTe₂ and Zr-MoTe₂ for CH₃CHO was between the H and Te atoms, and the distances were increased, with E_ads of −0.386 eV and −0.439 eV, respectively. After W-MoTe₂ and Zr-MoTe₂ adsorbed C₆H₆, both of the C₆H₆ molecules were parallel to the substrate, and the E_ads decreased compared to the original. From this, it can be seen that the adsorption energy of the modification system for gases decreases, and the adsorption ability of the modified atoms between the substrate and the CO, CH₃CHO, C₆H₆ gases weakens.

2.2.2. Electronic Analysis

To gain a detailed understanding and study of the behavior and properties of the electrons during the adsorption process, Figure 5 and Figure 6 depict the charge density difference (CDD) and the density of states (DOS) of the gas adsorption on the Metal-MoTe₂ monolayers. For the adsorption calculation, the Hirshfeld method is used to calculate the charge transfer during the adsorption process, which can better reflect the actual distribution of electron clouds [52]. Using the Hirshfeld charge analysis method, Q_t defines the amount of charge transferred from the gas molecules to the surface. Q_t < 0 indicates the transfer of electrons from the surface to the gas molecules.

From Figure 5(a,a1,a2), it can be seen that the Co-MoTe₂ monolayer lost electrons as a donor when adsorbing CO, CH₃CHO and C₆H₆. The strong blue color near the Co atom indicated its significant influence on gas adsorption. In the CO/Co-MoTe₂ system, although the C atom lost electrons, the oxygen atom gained more electrons, thus CO overall gained electrons. In Figure 5(b,b1,b2), the V atom appeared with red around it, and the electron density decreased during the adsorption process. The charge transfer amount was the highest in the process of the V-MoTe₂ monolayer adsorption of CO, with a charge transfer amount of 0.832 e. It is worth noting that when V-MoTe₂ adsorbed C₆H₆, although both the V and Te atoms lost electrons, the electron density near the Mo atoms increased, resulting in a transfer of 0.22 e electrons from the gas to the substrate. When using four different substrates to adsorb CH₃CHO, the C atom in the aldehyde group of CH₃CHO showed a strong red color, indicating that the aldehyde group in acetaldehyde is prone to losing electrons during the adsorption process. In the Zr-MoTe₂ system, the charge transfer amount was relatively small, and as shown in Table 1, the adsorption distance was also large, indicating that the adsorption reaction may be a chemical reaction.

From Figure 6, gas adsorption affected the electronic properties of the substrate and the distribution of electrons at different energy states. In Figure 6a–c, the partial density of states (PDOS) distribution of the Co-3d orbital at the Fermi level was the largest, indicating that atomic modification had a significant impact on the conductivity of the material. After CO adsorption, the TDOS remained almost unchanged and exhibited weak adsorption. After adsorption of CH₃CHO, although the TDOS near the Fermi level remained almost unchanged, three new peaks appeared in the range of −10–−6 eV. Observing the PDOS graph, it can be seen that the new peaks were likely caused by the superposition of the gases’ molecular density of states. Unlike the previous two gases, after adsorbing C₆H₆, there was a significant increase in the TDOS in the valence band within the range of −6 eV to −2 eV, indicating that adsorption affected the electronic orbitals of the crystal. In the V-MoTe₂ system, as shown in Figure 6d, the TDOS shifted to the right, the TDOS near the Fermi level slightly increased, the gap between the valence band and the conduction band decreased, and the conductivity slightly increased. The charge transfer amount of CH₃CHO adsorbed in the V-MoTe₂ process was very small, which corresponded to the TDOS that remained almost unchanged at the Fermi level. The slight increase in the TDOS near −2 eV and within the range of −10 eV to −6 eV was mainly caused by the O-2p and H-1s orbitals of CH₃CHO. In Figure 6g, after CO adsorption on W-MoTe₂, the TDOS curve shifted to the right, with continuous valence, conduction bands, and continuous energy level distribution, which improved the conductivity of the system. In Figure 6h, the peaks of the W-5d, O-2p, and H-1s orbitals overlapped near −2 eV and within the range of −10 eV to −6 eV, indicating severe hybridization of the atomic orbitals and strong interatomic interactions. From Figure 6i, it can be seen that new peaks appeared in the TDOS near −14 eV, −9 eV, and −7 eV. At the same time, according to the PDOS, there was a significant hybridization of the W-3d orbital and the C-2p orbital near −6 eV and −4.5 eV. It is speculated that the appearance of the new peaks may be caused by electron redistribution in the substrate. After Zr-MoTe₂ adsorbed CO, the TDOS shifted to the left, and the TDOS near the Fermi level decreased. However, the valence and conduction bands were continuous, and electrons could freely transition between the different energy levels. Within the range of −5 eV to 0 eV, weak hybridization occurred between the Zr-4d orbital and the C-2p orbital. In Figure 6l, orbital hybridization was evident near −10.5 eV, −8 eV, −6 eV, and −4 eV. Therefore, the TDOS and conductivity slightly increased near the valence band.

2.2.3. Molecular Orbital Analysis

This work applied molecular orbital theory to analyze the changes in the electrical conductivity of materials after adsorbing gases. HOMO and LUMO refer to the highest occupied molecular orbital and the lowest unoccupied molecular orbital, respectively, and the absolute difference between the two is the size of the energy gap (E_g). The smaller the energy level difference, the easier it is for molecules to be excited, that is, the better the conductivity of the material. The electrons on the HOMO orbital are the easiest to remove, while the LUMO orbital is the easiest to obtain electrons.

Figure 7 shows the HOMO and LUMO on the Metal-MoTe₂ before and after gas molecule adsorption. As shown in Figure 7, LUMO and HOMO mainly distributed around the metal atoms and the Mo atoms. When the Metal-MoTe₂ monolayer adsorbed CH₃CHO and C₆H₆, there were no HOMO and LUMO near the gas, which corresponded to the small charge transfer between the substrate and the gas shown in Figure 5. In the Co-MoTe₂ system, after the adsorption of CO, CH₃CHO, and C₆H₆, the band gap changed little, with a variation of about 1%. In the V-MoTe₂ system, after adsorbing CO, the energy gap decreased by 23.4% and the conductivity increased. However, after adsorbing CH₃CHO and C₆H₆, the E_g increased by 1.4% and 1.6%, respectively. For W-MoTe₂, the E_g decreased after adsorbing all three gases, but the E_g changed the most after adsorbing CO, from 1.074 eV to 0.417 eV, with a change rate of 61.2%. The E_g values of the other two gases only slightly decreased. After Zr-MoTe₂ adsorbed CH₃CHO, the E_g value increased by 0.1%, while after adsorbing CO and C₆H₆, the E_g decreased by 66.4% and 1%, respectively. The reduction in E_g made it easier for electrons to jump between the valence band and conduction band, thereby improving the conductivity of the material.

2.3. Comparison of the Adsorption Performance in Different Systems

To better investigate the effect of the modified metal atoms (Co, V, W, Zr) on the gas adsorption performance of the pristine MoTe₂ monolayer, Figure 8 shows the adsorption distance, E_ads, E_g, and Q_t of the pristine MoTe₂ and the Metal-MoTe₂ adsorbed gas. Firstly, according to Figure 8, the adsorption energy of the substrate for the three gases significantly reduced after modification. CO molecules are inorganic small gas molecules, while CH₃CHO and C₆H₆ are organic small molecules. Generally speaking, adsorbents with lower adsorption energy typically have a larger specific surface area and more adsorption sites, which enables them to more effectively adsorb small gas molecules [52,53]. Secondly, the shortest atomic distance and Q_t of CO adsorbed after modification significantly decreased and increased compared with that before adsorption, while the shortest atomic distance and Q_t of CH₃CHO and C₆H₆ did not change significantly, indicating that the modification operation may not have significantly changed the adsorption capacity and charge transfer capacity of the substrate. Then, by modification with metal atoms, the decrease in E_g indicated that the energy required for electronic transitions was reduced, and the conductivity of the material was improved. Finally, Table 2 lists the adsorption characteristics and parameters of some of the two-dimensional gas sensitive materials for CO, CH₃CHO, and C₆H₆, which was helpful for performance comparison. From the comparison in Table 2, it was found that although the Metal-MoTe₂ monolayer had a larger shortest atomic distance for CO, CH₃CHO, and C₆H₆ gases, its adsorption energy was relatively moderate. Overall, the Metal-MoTe₂ monolayer was suitable for monitoring the concentration of hazardous gases such as CO, CH₃CHO, and C₆H₆, or for adsorbing gases.

2.4. Desorption Performance Analysis

Good desorption performance can not only help improve the sensitivity and selectivity of gas sensing materials, but also extend the service life and improve their anti-interference ability of gas sensing materials. Recovery time is an important parameter reflecting parsing performance, usually defined in Equation (1) [58,59]:

(1)$\tau ={\nu }_0^{-1}{e}^{(-E_{\mathrm{ads}}/K_{\mathrm{B}}T)}$

where v₀ is the trial frequency and K_B is the Boltzmann constant. It can be inferred that the temperature and E_ads have a significant impact on the recovery time. Figure 9 shows the recovery times of the Metal-MoTe₂ for CO, CH₃CHO, and C₆H₆ at 298 K, 348 K, and 398 K. From Figure 9a,c,d, it can be seen that the Co-MoTe₂ monolayer and the W-MoTe₂ monolayer had a short recovery time for hazardous gases in the range of 298 K to 398 K, which could quickly adapt to environmental changes and provide more real-time data feedback. This is particularly important for applications that require rapid response. The gas recovery time of the Zr-MoTe₂ monolayer was also acceptable. Co-MoTe₂, W-MoTe₂, and Zr-MoTe₂ are all ideal gas sensing materials for CO, CH₃CHO, and C₆H₆ gases with appropriate adsorption energies for gases. On the contrary, the V-MoTe₂ monolayer had a longer recovery time for the CO gas, which was not conducive to improving the material’s reuse rate. Therefore, V-MoTe₂ is suitable as a material for monitoring the concentration of CH₃CHO and C₆H₆, and can serve as an adsorbent for CO molecules.

3. Methods

All calculations in this study were performed based on the density functional theory using Dmol³ 8 (Bernard Delley, Switzerland). After consulting simulation literature on MoTe₂ [38,60,61], the Monkhorst–Pack K point grid was set to 7 × 7 × 1, and the generalized gradient approximation (GGA) PBE function to calculate the exchange correlation energy was used [62]. In all calculations, the convergence accuracy of the electron self-consistent field and the ion self-consistent field were 1.0 × 10⁻⁶ Ha and 1.0 × 10⁻⁵ Ha, respectively. The calculation parameters for the maximum displacement and the maximum force were set to 0.005 Å and 0.002 Ha/Å, respectively. In order to avoid the influence between the adjacent layers, a 4 × 4 × 1 supercell with a vacuum plate exceeding 20 Å was established [63]. In order to improve the accuracy and efficiency of the calculations and predict the magnetic properties of the materials, spin polarization was also used in the calculations [64].

4. Conclusions

This study applied the density functional theory to study the adsorption of the pristine MoTe₂ monolayer and Co, V, W, Zr-modified MoTe₂ monolayers for the hazardous gases CO, CH₃CHO, and C₆H₆ from the perspectives of structural optimization, adsorption structure analysis, electronic analysis, molecular orbital analysis, and desorption performance analysis. On the one hand, the structural optimization results showed that the Co, V, W, Zr-modified MoTe₂ form stable structures with large bind energy values of −7.264 eV, −9.144 eV, −5.624 eV, and −3.283 eV, respectively. On the other hand, the modified metal atom (Co, V, W, Zr) enhanced the conductivity of the MoTe₂ monolayer, and acted as active adsorption sites for the gas molecules. The adsorption performance of the different gases on the pristine MoTe₂ monolayer and Co, V, W, Zr-modified MoTe₂ monolayers were compared. The adsorption energy decreased after metal atom (Co, V, W, Zr) modification, which significantly reduced the gas desorption time. Based on DOS and the desorption performance analysis, Co, V, W, Zr-modified MoTe₂ monolayers showed different conductivity variation upon CO, CH₃CHO, and C₆H₆ adsorption, which plays a theoretical basis for preparing gas sensing materials with good sensitivity selectivity.

Author Contributions

Conceptualization, W.X.; methodology, Y.G.; software, Z.W.; validation, W.X.; formal analysis, W.X.; investigation, W.X.; resources, Z.W.; data curation, W.X.; writing—original draft, W.X.; writing—review and editing, Y.G.; visualization, Y.G.; supervision, Y.G.; project administration, Y.G. All authors have read and agreed to the published version of the manuscript.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Data are contained within the article.

Conflicts of Interest

The authors declare no conflicts of interest.

Footnotes

Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Figures and Tables

Figure 1. Optimization Structure of CO, CH3CHO, C6H6, and the MoTe2 monolayer, distance in Å.

Figure 2. The modification structure and charge density differences (CDD) of the Metal-MoTe2.

Figure 3. Energy band structure diagrams of the pristine MoTe2 and Metal-MoTe2.

Figure 4. The adsorption structures of the Metal-MoTe2.

Figure 5. The CDD of gas molecule adsorption on the Metal-MoTe2.

Figure 6. The TDOS and PDOS on the Metal-MoTe2 before and after gas molecule adsorption. (a,d,g,j) CO adsorption. (b,e,h,k) CH3CHO adsorption. (c,f,i,l) C6H6 adsorption.

Figure 7. HOMO and LUMO on the Metal-MoTe2 before and after gas molecule adsorption.

Figure 8. Comparisons of the band gap (a) and adsorption energy (b) of gas adsorption on the MoTe2 and Metal-MoTe2.

Figure 9. The recovery time of the Metal-MoTe2 on CO, CH3CHO, and C6H6 at 273 K, 298 K, and 318 K.

Table 1

The adsorption structure, adsorption distance, and E_ads of the gases on Metal-MoTe₂.

System	Structure	Distance (Å)	Eads (eV)
CO/Co-MoTe2	Figure 4a	C-Te:3.522	−0.167
CH3CHO/Co-MoTe2	Figure 4(a1)	C-Te:3.288	−0.392
C6H6/Co-MoTe2	Figure 4(a2)	H-Te:3.558	−0.667
CO/V-MoTe2	Figure 4b	C-V:1.925	−1.221
CH3CHO/V-MoTe2	Figure 4(b1)	H-Te:3.151	−0.405
C6H6/V-MoTe2	Figure 4(b2)	H-Te:3.447	−0.711
CO/W-MoTe2	Figure 4c	C-W:2.027	−0.515
CH3CHO/W-MoTe2	Figure 4(c1)	H-Te:3.383	−0.386
C6H6/W-MoTe2	Figure 4(c2)	C-Te:3.708	−0.618
CO/Zr-MoTe2	Figure 4d	C-Zr:2.348	−0.592
CH3CHO/Zr-MoTe2	Figure 4(d1)	H-Te:3.512	−0.439
C6H6/Zr-MoTe2	Figure 4(d2)	H-Te:3.685	−0.800

Table 2

The adsorption characteristics of different materials for detecting CO, CH₃CHO and C₆H₆.

Gas	Material	Eads (eV)	Qt (e)	Distance (Å)	Reference
CO	Ni-MoTe2	−2.23	0.729	1.750	[6]
	MoO3	−0.1	0.1	2.4	[54]
	Co-MoTe2	−0.167	−0.032	3.522	This work
	V-MoTe2	−1.221	−0.832	1.925
	W-MoTe2	−0.515	−0.119	2.027
	Zr-MoTe2	−0.592	−0.046	2.348
CH3CHO	Fe-MoS2	−1.77	−0.179	1.865	[55]
	Al-Graphene	−3.183	−0.208	/	[56]
	Co-MoTe2	−0.392	−0.084	3.288	This work
	V-MoTe2	−0.405	−0.082	3.151
	W-MoTe2	−0.386	−0.079	3.383
	Zr-MoTe2	−0.439	−0.063	3.512
C6H6	Fe-MoS2	−1.88	0.094	1.246	[55]
	Pd-GeSe	−0.51	0.050	/	[57]
	Co-MoTe2	−0.667	−0.083	3.558	This work
	V-MoTe2	−0.711	0.220	3.447
	W-MoTe2	−0.618	−0.063	3.708
	Zr-MoTe2	−0.800	−0.085	3.685

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/molecules29215086/s1, Table S1: The structure of MoTe2, CO, CH₃CHO, and C₆H₆ gases. References [65,66,67,68] are cited in the Supplementary Materials.

References

1. Beheshtian, J.; Baei, M.T.; Peyghan, A.A. Theoretical study of CO adsorption on the surface of BN, AlN, BP and AlP nanotubes. Surf. Sci.; 2012; 606, pp. 981-985. [DOI: https://dx.doi.org/10.1016/j.susc.2012.02.019]

2. Chen, H.; Cox, D.F. CO adsorption on MnO (100): Experimental benchmarks compared to DFT. Surf. Sci.; 2021; 707, 121808. [DOI: https://dx.doi.org/10.1016/j.susc.2021.121808]

3. Neri, G.; Bonavita, A.; Micali, G.; Rizzo, G.; Callone, E.; Carturan, G. Resistive CO gas sensors based on In₂O₃ and InSnOx nanopowders synthesized via starch-aided sol–gel process for automotive applications. Sens. Actuators B Chem.; 2008; 132, pp. 224-233. [DOI: https://dx.doi.org/10.1016/j.snb.2008.01.030]

4. Kozina, A.; Radica, G.; Nižetić, S. Analysis of methods towards reduction of harmful pollutants from diesel engines. J. Clean. Prod.; 2020; 262, 121105. [DOI: https://dx.doi.org/10.1016/j.jclepro.2020.121105]

5. Sokolnicka, B.; Fuć, P.; Szymlet, N.; Siedlecki, M.; Grzeszczyk, R. Harmful exhaust components and particles mass and number emission during the actual drive of a passenger car in accordance with the RDE procedure. Combust. Engines; 2019; 58, pp. 198-202. [DOI: https://dx.doi.org/10.19206/CE-2019-334]

6. Wang, M.; Cheng, S.; Zeng, W.; Zhou, Q. Adsorption of toxic and harmful gas CO on TM (Ni, Pd, Pt) doped MoTe₂ monolayer: A DFT study. Surf. Interfaces; 2022; 31, 102111. [DOI: https://dx.doi.org/10.1016/j.surfin.2022.102111]

7. Kim, J.M.; Kim, J.H.; Lee, C.Y.; Jerng, D.W.; Ahn, H.S. Toluene and acetaldehyde removal from air on to graphene-based adsorbents with microsized pores. J. Hazard. Mater.; 2018; 344, pp. 458-465. [DOI: https://dx.doi.org/10.1016/j.jhazmat.2017.10.038]

8. Wang, H.; Shao, Z.; Shi, X.; Tang, Z.; Sun, B. Rapidly detecting the carcinogen acetaldehyde: Preparation and application of a flower-like MoS₂ cataluminescence sensor at low working temperature. Anal. Methods; 2023; 15, pp. 5620-5629. [DOI: https://dx.doi.org/10.1039/D3AY01307C]

9. Galbraith, D.; Gross, S.A.; Paustenbach, D. Benzene and human health: A historical review and appraisal of associations with various diseases. Crit. Rev. Toxicol.; 2010; 40, pp. 1-46. [DOI: https://dx.doi.org/10.3109/10408444.2010.508162]

10. Gui, Y.; Luo, P.; Ji, C.; Lin, Y.; Chen, X. First-principles study of the gas sensing of benzene and formaldehyde by Ag₂O-and CuO-modified MoSe₂ nanosheets. ACS Appl. Nano Mater.; 2022; 5, pp. 12907-12914. [DOI: https://dx.doi.org/10.1021/acsanm.2c02753]

11. Zhang, G.; Hua, B.; Dey, A.; Ghosh, M.; Moosa, B.A.; Khashab, N.M. Intrinsically porous molecular materials (IPMs) for natural gas and benzene derivatives separations. Acc. Chem. Res.; 2020; 54, pp. 155-168. [DOI: https://dx.doi.org/10.1021/acs.accounts.0c00582] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/33332097]

12. Kim, B.R. VOC emissions from automotive painting and their control: A review. Environ. Eng. Res.; 2011; 16, pp. 1-9. [DOI: https://dx.doi.org/10.4491/eer.2011.16.1.001]

13. Yang, S.; Yang, X.; Licina, D. Emissions of volatile organic compounds from interior materials of vehicles. Build. Environ.; 2020; 170, 106599. [DOI: https://dx.doi.org/10.1016/j.buildenv.2019.106599]

14. Gao, M.; Liu, W.; Wang, H.; Shao, X.; Shi, A.; An, X.; Li, G.; Nie, L. Emission factors and characteristics of volatile organic compounds (VOCs) from adhesive application in indoor decoration in China. Sci. Total Environ.; 2021; 779, 145169. [DOI: https://dx.doi.org/10.1016/j.scitotenv.2021.145169]

15. Abbasi, A.; Abdelrasoul, A.; Sardroodi, J.J. Adsorption of CO and NO molecules on Al, P and Si embedded MoS₂ nanosheets investigated by DFT calculations. Adsorption; 2019; 25, pp. 1001-1017. [DOI: https://dx.doi.org/10.1007/s10450-019-00121-6]

16. Abbasi, A.; Sardroodi, J.J. Investigation of the adsorption of ozone molecules on TiO₂/WSe₂ nanocomposites by DFT computations: Applications to gas sensor devices. Appl. Surf. Sci.; 2018; 436, pp. 27-41. [DOI: https://dx.doi.org/10.1016/j.apsusc.2017.12.010]

17. Abbasi, A.; Sardroodi, J.J. Theoretical study of the adsorption of NOx on TiO₂/MoS₂ nanocomposites: A comparison between undoped and N-doped nanocomposites. J. Nanostruct. Chem.; 2016; 6, pp. 309-327. [DOI: https://dx.doi.org/10.1007/s40097-016-0204-3]

18. Abbasi, A.; Jahanbin Sardroodi, J. Prediction of a highly sensitive molecule sensor for SOx detection based on TiO₂/MoS₂ nanocomposites: A DFT study. J. Sulfur Chem.; 2017; 38, pp. 52-68. [DOI: https://dx.doi.org/10.1080/17415993.2016.1229782]

19. Ibrahim, K.B.; Shifa, T.A.; Zorzi, S.; Sendeku, M.G.; Moretti, E.; Vomiero, A. Emerging 2D materials beyond mxenes and TMDs: Transition metal carbo-chalcogenides. Prog. Mater. Sci.; 2024; 144, 101287.

20. Li, T.; Li, H.; Yuan, J.; Xia, Y.; Liu, Y.; Sun, A. Recent advance and modification strategies of transition metal dichalcogenides (TMDs) in aqueous zinc ion batteries. Materials; 2022; 15, 2654. [DOI: https://dx.doi.org/10.3390/ma15072654]

21. Roy, S.; Neupane, G.P.; Dhakal, K.P.; Lee, J.; Yun, S.J.; Han, G.H.; Kim, J. Observation of charge transfer in heterostructures composed of MoSe₂ quantum dots and a monolayer of MoS₂ or WSe₂. J. Phys. Chem. C; 2017; 121, pp. 1997-2004. [DOI: https://dx.doi.org/10.1021/acs.jpcc.6b11778]

22. Gusakova, J.; Wang, X.; Shiau, L.L.; Krivosheeva, A.; Shaposhnikov, V.; Borisenko, V.; Gusakov, V.; Tay, B.K. Electronic properties of bulk and monolayer TMDs: Theoretical study within DFT framework (GVJ-2e method). Phys. Status Solidi A; 2017; 214, 1700218. [DOI: https://dx.doi.org/10.1002/pssa.201700218]

23. Li, E.; Wang, F.; Cui, Z.; Ma, D.; Shen, Y.; Shen, P.; Zhao, H.; Tang, Y. Electronic properties of van der Waals heterostructures based on F-GaN-H stacking and TMDs single layer. Vacuum; 2022; 206, 111546. [DOI: https://dx.doi.org/10.1016/j.vacuum.2022.111546]

24. Babariya, B.; Gupta, S.K.; Gajjar, P. Theoretical designing of TMDs Janus heterostructures toward efficient photovoltaic and electronic applications. Surf. Interfaces; 2023; 42, 103409. [DOI: https://dx.doi.org/10.1016/j.surfin.2023.103409]

25. Komsa, H.-P.; Krasheninnikov, A.V. Electronic structures and optical properties of realistic transition metal dichalcogenide heterostructures from first principles. Phys. Rev. B; 2013; 88, 085318. [DOI: https://dx.doi.org/10.1103/PhysRevB.88.085318]

26. Voshell, A.; Terrones, M.; Rana, M. Review of optical properties of two-dimensional transition metal dichalcogenides. Wide Bandgap Power Energy Devices Appl. III; 2018; 10754, pp. 66-83.

27. Sorkin, V.; Pan, H.; Shi, H.; Quek, S.; Zhang, Y. Nanoscale transition metal dichalcogenides: Structures, properties, and applications. Crit. Rev. Solid State Mater. Sci.; 2014; 39, pp. 319-367. [DOI: https://dx.doi.org/10.1080/10408436.2013.863176]

28. Zhao, B.; Shen, D.; Zhang, Z.; Lu, P.; Hossain, M.; Li, J.; Li, B.; Duan, X. 2D metallic transition-metal dichalcogenides: Structures, synthesis, properties, and applications. Adv. Funct. Mater.; 2021; 31, 2105132. [DOI: https://dx.doi.org/10.1002/adfm.202105132]

29. Feng, Z.; Xie, Y.; Wu, E.; Yu, Y.; Zheng, S.; Zhang, R.; Chen, X.; Sun, C.; Zhang, H.; Pang, W. Enhanced sensitivity of MoTe₂ chemical sensor through light illumination. Micromachines; 2017; 8, 155. [DOI: https://dx.doi.org/10.3390/mi8050155]

30. Li, C.; Tian, R.; Chen, X.; Gu, L.; Luo, Z.; Zhang, Q.; Yi, R.; Li, Z.; Jiang, B.; Liu, Y. Waveguide-integrated MoTe₂ p–i–n homojunction photodetector. ACS Nano; 2022; 16, pp. 20946-20955. [DOI: https://dx.doi.org/10.1021/acsnano.2c08549]

31. Li, C.; Tian, R.; Yi, R.; Hu, S.; Chen, Y.; Yuan, Q.; Zhang, X.; Liu, Y.; Hao, Y.; Gan, X. MoTe₂ PN homojunction constructed on a silicon photonic crystal cavity for high-performance photodetector. ACS Photonics; 2021; 8, pp. 2431-2439. [DOI: https://dx.doi.org/10.1021/acsphotonics.1c00628]

32. Luo, X.; Chen, F.; Zhang, J.; Pei, Q.; Lin, G.; Lu, W.; Han, Y.; Xi, C.; Song, W.; Sun, Y. Td-MoTe₂: A possible topological superconductor. Appl. Phys. Lett.; 2016; 109, 102601. [DOI: https://dx.doi.org/10.1063/1.4962466]

33. Sankar, R.; Rao, G.N.; Muthuselvam, I.P.; Butler, C.; Kumar, N.; Murugan, G.S.; Shekhar, C.; Chang, T.-R.; Wen, C.-Y.; Chen, C.-W. Polymorphic layered MoTe₂ from semiconductor, topological insulator, to Weyl semimetal. Chem. Mater.; 2017; 29, pp. 699-707. [DOI: https://dx.doi.org/10.1021/acs.chemmater.6b04363]

34. Wang, Z.; Gresch, D.; Soluyanov, A.A.; Xie, W.; Kushwaha, S.; Dai, X.; Troyer, M.; Cava, R.J.; Bernevig, B.A. MoTe₂: A type-II Weyl topological metal. Phys. Rev. Lett.; 2016; 117, 056805. [DOI: https://dx.doi.org/10.1103/PhysRevLett.117.056805]

35. Deng, Y.; Zhao, X.; Zhu, C.; Li, P.; Duan, R.; Liu, G.; Liu, Z. MoTe₂: Semiconductor or semimetal?. ACS Nano; 2021; 15, pp. 12465-12474. [DOI: https://dx.doi.org/10.1021/acsnano.1c01816]

36. Wang, Y.; Zhang, M.; Xue, Z.; Chen, X.; Mei, Y.; Chu, P.K.; Tian, Z.; Wu, X.; Di, Z. Atomistic observation of the local phase transition in MoTe₂ for application in homojunction photodetectors. Small; 2022; 18, 2200913. [DOI: https://dx.doi.org/10.1002/smll.202200913]

37. Ahmed, F.; Shafi, A.M.; Mackenzie, D.M.; Qureshi, M.A.; Fernandez, H.A.; Yoon, H.H.; Uddin, M.G.; Kuittinen, M.; Sun, Z.; Lipsanen, H. Multilayer MoTe₂ Field-Effect Transistor at High Temperatures. Adv. Mater. Interfaces; 2021; 8, 2100950. [DOI: https://dx.doi.org/10.1002/admi.202100950]

38. Gui, Y.; Zhang, W.; Liu, S.; Li, Y.; Yang, J.; Jin, G.; Huang, H.; Yang, P.; Gao, M. Self-driven sensing of acetylene powered by a triboelectric-electromagnetic hybrid generator. Nano Energy; 2024; 124, 109498. [DOI: https://dx.doi.org/10.1016/j.nanoen.2024.109498]

39. Zhang, W.; Gui, Y.; Yang, Y.; Tang, C. A hybrid nanogenerator based on wind energy harvesting for powering self-driven sensing systems. J. Clean. Prod.; 2023; 429, 139550. [DOI: https://dx.doi.org/10.1016/j.jclepro.2023.139550]

40. Said, A.E.-A.A.; El-Aal, M.A. Direct dehydrogenation of methanol to anhydrous formaldehyde over Ag₂O/γ-Al₂O₃ nanocatalysts at relatively low temperature. Res. Chem. Intermed.; 2017; 43, pp. 3205-3217. [DOI: https://dx.doi.org/10.1007/s11164-016-2820-4]

41. Wang, Y.; Gui, Y.; He, S.; Yang, J. Hybrid nanogenerator driven self-powered SO₂F₂ sensing system based on TiO₂/Ni/C composites at room temperature. Sens. Actuators B Chem.; 2023; 377, 133053. [DOI: https://dx.doi.org/10.1016/j.snb.2022.133053]

42. Wang, M.; Zhou, Q.; Zeng, W. Theoretical study on adsorption of SF6 decomposition gas in GIS gas cell based on intrinsic and Ni-doped MoTe₂ monolayer. Appl. Surf. Sci.; 2022; 591, 153167. [DOI: https://dx.doi.org/10.1016/j.apsusc.2022.153167]

43. Lin, L.; Feng, Z.; Dong, Z.; Hu, C.; Han, L.; Tao, H. DFT study on the adsorption of CO, NO₂, SO₂ and NH₃ by Te vacancy and metal atom doped MoTe₂ monolayers. Phys. E Low-Dimens. Syst. Nanostruct.; 2023; 145, 115489. [DOI: https://dx.doi.org/10.1016/j.physe.2022.115489]

44. Han, X.; Hong, Y.; Ma, Y.; Lu, W.; Li, J.; Lin, L.; Sheveleva, A.M.; Tuna, F.; McInnes, E.J.; Dejoie, C. Adsorption of nitrogen dioxide in a redox-active vanadium metal–organic framework material. J. Am. Chem. Soc.; 2020; 142, pp. 15235-15239. [DOI: https://dx.doi.org/10.1021/jacs.0c06414]

45. Zhang, Y.; Shao, S.; Ye, P.; Zhang, L.; Shen, X.; Huang, Q.; Xu, H.; Liu, H.; Li, S. In Situ Synthesis of Hierarchical Porous Zr-MOFs on Columnar Activated Carbon and Application in Toxic Gas Adsorption. Inorg. Chem.; 2022; 61, pp. 18355-18364. [DOI: https://dx.doi.org/10.1021/acs.inorgchem.2c01398]

46. Zhang, X.; Chen, D.; Cui, H.; Dong, X.; Xiao, S.; Tang, J. Understanding of SF₆ decompositions adsorbed on cobalt-doped SWCNT: A DFT study. Appl. Surf. Sci.; 2017; 420, pp. 371-382. [DOI: https://dx.doi.org/10.1016/j.apsusc.2017.05.163]

47. Zhao, R.; Chen, D.; Li, J.; Miao, Q.; Liu, K.; Xiao, B. Adsorption and Sensing Mechanism of Late Transition Metal Doped MoTe₂ Monolayers for Dissolved Gas Analysis in Transformer Oil: A First-Principles Study. IEEE Sens. J.; 2024; 24, pp. 9317-9325. [DOI: https://dx.doi.org/10.1109/JSEN.2024.3360965]

48. Joshi, A.; Rammohan, A.; Jiang, Y.; Ogunwumi, S. Density functional theory (DFT) study of the interaction of ammonia with pure and tungsten–doped ceria. J. Mol. Struct. THEOCHEM; 2009; 912, pp. 73-81. [DOI: https://dx.doi.org/10.1016/j.theochem.2009.04.030]

49. Yang, S.; Xie, S.; Tan, L.; Lei, G.; Xu, H.; Lan, Z.; Wang, Z.; Gu, H. Selective and tunable H₂ adsorption/sensing performance of W-doped graphene under external electric fields: A DFT study. Int. J. Hydrogen Energy; 2022; 47, pp. 29579-29591. [DOI: https://dx.doi.org/10.1016/j.ijhydene.2022.06.259]

50. Gui, Y.; Wang, Y.; He, S.; Yang, J. Self-powered smart agriculture real-time sensing device based on hybrid wind energy harvesting triboelectric-electromagnetic nanogenerator. Energy Convers. Manag.; 2022; 269, 116098. [DOI: https://dx.doi.org/10.1016/j.enconman.2022.116098]

51. He, S.; Gui, Y.; Wang, Y.; Yang, J. A self-powered β-Ni(OH)₂/MXene based ethanol sensor driven by an enhanced triboelectric nanogenerator based on β-Ni(OH)₂@PVDF at room temperature. Nano Energy; 2023; 107, 108132. [DOI: https://dx.doi.org/10.1016/j.nanoen.2022.108132]

52. Saha, S.; Roy, R.K.; Ayers, P.W. Are the Hirshfeld and Mulliken population analysis schemes consistent with chemical intuition?. Int. J. Quantum Chem.; 2009; 109, pp. 1790-1806. [DOI: https://dx.doi.org/10.1002/qua.21901]

53. Gautier, S.; Steinmann, S.N.; Michel, C.; Fleurat-Lessard, P.; Sautet, P. Molecular adsorption at Pt (111). How accurate are DFT functionals?. Phys. Chem. Chem. Phys.; 2015; 17, pp. 28921-28930. [DOI: https://dx.doi.org/10.1039/C5CP04534G] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/26455444]

54. Xu, K.; Liao, N.; Zheng, B.; Zhou, H. Adsorption and diffusion behaviors of H₂, H₂S, NH₃, CO and H₂O gases molecules on MoO₃ monolayer: A DFT study. Phys. Lett. A; 2020; 384, 126533. [DOI: https://dx.doi.org/10.1016/j.physleta.2020.126533]

55. Ni, J.; Yang, Z.; Shen, Y.; Xie, J.; Zhang, T.; Wang, S.; Chen, Y. Volatile organic compounds gas molecule adsorption on Fe-MoS₂ monolayer: The first-principles study. Chem. Phys. Lett.; 2023; 813, 140298. [DOI: https://dx.doi.org/10.1016/j.cplett.2023.140298]

56. Liu, B.; Zhao, W.; Jiang, Q.; Ao, Z.; An, T. Enhanced adsorption mechanism of carbonyl-containing volatile organic compounds on Al-decorated porous graphene monolayer: A density functional theory calculation study. Sustain. Mater. Technol.; 2019; 21, e00103. [DOI: https://dx.doi.org/10.1016/j.susmat.2019.e00103]

57. Guo, G.; Min, J.; Xu, Y.; Zhou, Y.; Xu, G. Gas Sensing Properties of Pd-Decorated GeSe Monolayer toward Formaldehyde and Benzene Molecules: A First-Principles Study. Langmuir; 2023; 40, pp. 997-1006. [DOI: https://dx.doi.org/10.1021/acs.langmuir.3c03221]

58. Mehdi Aghaei, S.; Monshi, M.M.; Torres, I.; Zeidi, S.M.J.; Calizo, I. DFT study of adsorption behavior of NO, CO, NO₂, and NH₃ molecules on graphene-like BC₃: A search for highly sensitive molecular sensor. Appl. Surf. Sci.; 2018; 427, pp. 326-333. [DOI: https://dx.doi.org/10.1016/j.apsusc.2017.08.048]

59. Zhang, W.; Tang, J.; Yuan, H.; Li, K.; Liu, H.; Zhu, H.; Zhang, T.; Jiang, T. Adsorption and Sensing Performance of Vented Gases from Lithium-Ion Batteries on Transition-Metal-Doped GeTe Nanosheets: A DFT Investigation. ACS Appl. Nano Mater.; 2023; 6, pp. 4056-4066. [DOI: https://dx.doi.org/10.1021/acsanm.3c00583]

60. Feng, Z.; Lin, L.; Su, L.; Pang, D.; Shi, P. Mechanism of adsorption of hazardous gases by MoTe₂ monolayers modified with nanoclusters. J. Environ. Chem. Eng.; 2023; 11, 110486. [DOI: https://dx.doi.org/10.1016/j.jece.2023.110486]

61. Shi, Z.; Zhang, J.; Zeng, W.; Zhou, Q. Adsorption and sensing performances of MoTe₂ monolayers doped with Pd, Ni, and Pt for SO₂ and NH₃: A DFT investigation. Langmuir; 2023; 39, pp. 4125-4139. [DOI: https://dx.doi.org/10.1021/acs.langmuir.3c00030] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/36883815]

62. He, S.; Gui, Y.; Wang, Y.; Cao, L.; He, G.; Tang, C. CuO/TiO₂/MXene-based sensor and SMS-TENG array integrated inspection robots for self-powered ethanol detection and alarm at room temperature. ACS Sens.; 2024; 9, pp. 1188-1198. [DOI: https://dx.doi.org/10.1021/acssensors.3c01963] [PubMed: https://www.ncbi.nlm.nih.gov/pubmed/38358362]

63. Cao, W.; Zhao, Q.; Yang, L.; Cui, H. Enhanced NOx adsorption and sensing properties of MoTe₂ monolayer by Ni-doping: A first-principles study. Surf. Interfaces; 2021; 26, 101372. [DOI: https://dx.doi.org/10.1016/j.surfin.2021.101372]

64. Li, X.; Ma, Y.; Zhou, W.; Liu, Z. Spin-polarized DFT calculations of elemental effects on hydrogen atom adsorption on FeCrAl (1 1 0) surface. Appl. Surf. Sci.; 2022; 581, 152273. [DOI: https://dx.doi.org/10.1016/j.apsusc.2021.152273]

65. Wang, Y.; Xiao, J.; Zhu, H.; Li, Y.; Alsaid, Y.; Fong, K.Y.; Zhou, Y.; Wang, S.; Shi, W.; Wang, Y. et al. Structural phase transition in monolayer MoTe2 driven by electrostatic doping. Nature; 2017; 550, pp. 487-491. [DOI: https://dx.doi.org/10.1038/nature24043]

66. Xue, W.; Wang, Z.-C.; He, S.-G.; Xie, Y.; Bernstein, E.R. Experimental and Theoretical Study of the Reactions between Small Neutral Iron Oxide Clusters and Carbon Monoxide. J. Am. Chem. Soc.; 2008; 130, pp. 15879-15888. [DOI: https://dx.doi.org/10.1021/ja8023093]

67. Stevenson, D.P.; Burnham, H.D.; Schomaker, V. The Molecular Structure of Acetaldehyde. J. Am. Chem. Soc.; 1939; 61, pp. 2922-2925. [DOI: https://dx.doi.org/10.1021/ja01265a099]

68. Baltzer, P.; Karlsson, L.; Wannberg, B.; Öhrwall, G.; Holland, D.M.P.; MacDonald, M.A.; Hayes, M.A.; von Niessen, W. An experimental and theoretical study of the valence shell photoelectron spectrum of the benzene molecule. Chem. Phys.; 1997; 224, pp. 95-119. [DOI: https://dx.doi.org/10.1016/S0301-0104(97)00244-9]