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A magnetic nanosensor for flammable VOCs detection: unveiling Mn2SO2 monolayer performance through ab initio modelling
(2026-06-30)
Oo, Ghaim Man
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Khammuang, Satchakorn
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Udomkijmongkol, Anan
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Thasitha, Sirinee
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Ounrit, Iyarat
Effective victim detection during fire disasters requires reliable identification of flammable VOCs under high-temperature conditions. Magnetic VOC sensors based on two-dimensional nanomaterials offer a promising solution. In this work, a Mn<inf>2</inf>SO<inf>2</inf> monolayer is investigated as a magnetic VOC sensor for eleven fire-related VOCs using density functional theory (DFT). Mn<inf>2</inf>SO<inf>2</inf> exhibits intrinsic spin polarization and ferromagnetism that support magnetic sensing. Adsorption results show strong chemisorption for Benzaldehyde, Butanol, Heptane, Hexanal, Methylamine, Dimethyl disulfide, Dimethyl trisulfide, Pyridine, and Toluene, with adsorption energies from −1.53 to −0.46 eV, whereas Butanone (−0.34 eV) and Octane (−0.12 eV) show weak physisorption. Charge transfer, electron density difference, and ELF analyses reveal predominantly ionic interactions, with Mn<inf>2</inf>SO<inf>2</inf> acting as an electron acceptor. Sensor responsiveness assessed via work-function modulation and magnetic-moment variation indicates high sensitivity, particularly for Pyridine (42.81%), Dimethyl disulfide (33.07%), Butanol (15.57%), and Toluene (15.84%). Ab initio molecular dynamics at 400 K confirm thermal stability and structural integrity on the picosecond timescale. Pyridine and Dimethyl disulfide emerge as the most promising detection targets due to high sensitivity and fast recovery times. These results highlight Mn<inf>2</inf>SO<inf>2</inf> as a promising candidate for the future generation of magnetic VOC sensors in fire-disaster victim detection.
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Metal anchoring-induced enhancement of Ψ-graphene gas sensors for CH4, CO, and CO2 monitoring
(2026-05-01)
Khammuang, Satchakorn
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Wongphen, Kantaphong
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Hussain, Tanveer
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Kotmool, Komsilp
Metal-anchored Ψ-graphene (Ψ-G@M; M = Cu, Ag, Pd, and Pt) systems were systematically investigated using first-principles calculations to assess their structural stability, electronic properties, and gas-sensing performance toward CH<inf>4</inf>, CO, and CO<inf>2</inf>. Structural analysis indicates that all metal atoms can be stably anchored on the Ψ-graphene surface, with stability following the order Pt > Pd > Cu > Ag based on formation energies and adsorption distances. Electronic structure analyses, including partial density of states (PDOS), electron density difference (EDD), Bader charge, and electron localization function (ELF), reveal stronger orbital hybridization between Pd and Pt with the C-2p states of Ψ-graphene, suggesting partially covalent interactions, whereas Cu and Ag exhibit weaker hybridization and more localized electronic distributions. All metal-anchored systems preserve the intrinsic non-magnetic character of Ψ-graphene. Gas adsorption results demonstrate that CH<inf>4</inf> adsorption on Ψ-G@Cu, Ψ-G@Pd, and Ψ-G@Pt, CO adsorption on Ψ-G@Ag, and CO<inf>2</inf> adsorption on Ψ-G@Cu, Ψ-G@Pd, and Ψ-G@Pt fall within the optimal adsorption energy range (-0.50 to -1.20 eV), providing a suitable balance between adsorption strength and reversible desorption for sensing applications. In contrast, the exceptionally strong adsorption of CO on Ψ-G@Cu, Ψ-G@Pd, and Ψ-G@Pt suggests that these systems are more suitable for gas capture than for reversible sensing. Work function modulation and sensitivity analyses reveal that CH<inf>4</inf> adsorption on Ψ-G@Cu and CO<inf>2</inf> adsorption on Ψ-G@Cu, Ψ-G@Pd, and Ψ-G@Pt exhibit sensitivity values exceeding 10%, indicating significant electronic responses upon gas adsorption. Recovery time calculations further demonstrate rapid desorption of CH<inf>4</inf> on Ψ-G@Cu and Ψ-G@Pd, and of CO<inf>2</inf> on Ψ-G@Cu and Ψ-G@Pd, at 300 K, suggesting excellent reversibility and fast sensing capability. Ab initio molecular dynamics simulations confirm that the sensing systems, CH<inf>4</inf>-Ψ-G@Cu and CO<inf>2</inf>-Ψ-G@Pd, remain structurally stable at both 300 K and 500 K, demonstrating strong thermal stability under operating and regeneration conditions. These findings highlight that Cu- and Pd-anchored Ψ-graphene are promising candidates for high-performance CH<inf>4</inf> and CO<inf>2</inf> gas sensing with high sensitivity, rapid recovery, and robust thermal stability.
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Inhibiting the shuttle effect in sodium-sulfur batteries using Mo2CT2(T = S, O) MXenes: A DFT investigation
(2026-03-30)
Udomkijmongkol, Anan
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Ruttanapunt, Piyaphat
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Thasitha, Sirinee
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Ounrit, Iyarat
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Khammuang, Satchakorn
The rising demand for electrification has highlighted sodium–sulfur (Na–S) batteries as a promising energy-storage technology due to their high theoretical capacity, abundant materials, and low cost. However, their performance is limited by polysulfide dissolution, or the shuttle effect, which slows redox kinetics and accelerates capacity fading. This study employs the DFT method to investigate Mo<inf>2</inf>CT<inf>2</inf> (T = S, O) MXenes in 1T and 2H phases as potential anchoring materials for sulfur cathodes. All Mo<inf>2</inf>CT<inf>2</inf> structures effectively adsorb sodium polysulfides (Na<inf>2</inf>S<inf>n</inf>), demonstrating higher adsorption strength than commercial electrolytes and effectively suppressing the shuttle effect. Structural phase notably affects Na<inf>2</inf>S<inf>n</inf> adsorption on Mo<inf>2</inf>CS<inf>2</inf>, while its influence is minor for Mo<inf>2</inf>CO<inf>2</inf>. Higher Na<inf>2</inf>S<inf>n</inf>-Mo<inf>2</inf>CO<inf>2</inf> interaction arises from greater charge transfer from Na to O atom driven by higher electronegativity difference. Among the candidates, 2H-Mo<inf>2</inf>CS<inf>2</inf> and 1T-Mo<inf>2</inf>CO<inf>2</inf> exhibit higher binding energies than its counterpart and maintain metallic conductivity after Na<inf>2</inf>S<inf>n</inf> adsorption, benefiting electron transport. Gibbs free energy calculations indicate more favorable sulfur reduction pathways on Mo<inf>2</inf>CT<inf>2</inf> surfaces, along with reduced energy barriers for Na<inf>2</inf>S oxidation. Overall, Mo<inf>2</inf>CT<inf>2</inf> MXenes exhibit strong anchoring capability and catalytic activity, making them promising materials for mitigating the shuttle effect and enhancing electrochemical performance in Na–S batteries.
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Ab initio investigation of NO capture by Fe/Co/Ni‑doped biphenylene monolayers
(2026-02-15)
Wongphen, Kantaphong
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Khammuang, Satchakorn
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Hussain, Tanveer
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Kotmool, Komsilp
We employ first-principles density functional theory (DFT) calculations to explore the potential of Fe-, Co–, and Ni-doped biphenylene (BP) monolayers as efficient materials for nitric oxide (NO) gas detection and capture. Our results reveal strong chemisorption of NO gas, with adsorption energies of −2.820, −2.016, and −2.504 eV, respectively. Spin-polarized partial density of states (PDOS) analysis indicates notable magnetic modulation upon NO adsorption, particularly the quenching of spin in Fe-doped BP and induced asymmetric spin polarization in Co– and Ni-doped systems. Charge transfer analysis, as determined by Bader charge, electron density difference (EDD), and electron localization function (ELF), confirms significant electron donation from the doped surfaces to the NO molecule, correlating with an enhanced adsorption strength. Metal doping significantly reduces the work function (ϕ) value of the BP monolayer, while subsequent NO adsorption slightly increases due to electron transfer from the metal dopants to the NO gas. Moreover, ab initio molecular dynamics (AIMD) simulations at 300 K demonstrate the thermal stability of the NO-adsorbed configurations, reinforcing the feasibility of these systems under ambient temperature. Collectively, our findings highlight the strong interaction between NO gas and metal-doped BP monolayers (M@BP), underscoring their promise for advanced NO gas storage and sensing technologies.
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Modulating WS2 surface reactivity via Nb decoration: A DFT study of gas interaction, sensing, and storage potential
(2026-01-15)
Wongphen, Kantaphong
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Ruttanapunt, Piyaphat
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Khammuang, Satchakorn
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Hussain, Tanveer
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Kotmool, Komsilp
In this study, we employ first-principles density functional theory (DFT) to investigate the electronic, magnetic, and thermodynamic properties of niobium-decorated tungsten disulfide (Nb@WS<inf>2</inf>), a potential material for gas capture and sensing. The adsorption behavior of CO, HCHO, NO, and NO<inf>2</inf> was systematically investigated. Adsorption energies (E<inf>ads</inf>) range from −1.481 eV (CO) to −3.290 eV (NO<inf>2</inf>), with NO<inf>2</inf> exhibiting the strongest interaction due to the high difference in electronegativity between interacting N and Nb atoms. Partial density of states (PDOS), Bader charge analysis, electron density difference (EDD), and electron localization function (ELF) collectively reveal significant charge transfer from Nb@WS<inf>2</inf> to gas molecules, confirming the chemisorption nature of the interactions and the emergence of distinct electronic and magnetic signatures. Work function analysis showed notable increases upon gas adsorption, correlating with sensitivity enhancements of up to 18.24 % for NO. However, the elevated E<inf>ads</inf> values observed in these systems, leading to their enormous recovery times, pose specific challenges for their practical use as reusable gas sensors. Moreover, ab initio molecular dynamics (AIMD) simulations at 500 K confirm the thermal stability of gas-adsorbed configurations, reinforcing the viability of Nb@WS<inf>2</inf> for high-temperature sensing or capturing applications.
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WS2Nanosheet-Based Sensors for Efficient Detection and Removal of Potentially Toxic Elements: A DFT Investigation
(2025-08-08)
Panigrahi, Puspamitra
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PS, Anuroop
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Pal, Yash
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Sharma, Munish
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Bae, Hyeonhu
This study presents a computational approach for designing nanosensors based on two-dimensional tungsten disulfide (WS<inf>2</inf>) monolayers for detecting potentially toxic elements (PTEs), including silver (Ag), arsenic (As), chromium (Cr), cadmium (Cd), mercury (Hg), and lead (Pb). Using first-principles density functional theory (DFT) calculations, the sensing performance of WS<inf>2</inf>-based materials was assessed in both atmospheric and aqueous conditions. To enhance the inherently weak adsorption and limited electronic interaction of pristine WS<inf>2</inf>with PTEs, its carrier concentration was modulated by introducing sulfur vacancies (WS<inf>2</inf>–S<inf>v</inf>) and doping with low concentrations (1.33%) of carbon (WS<inf>2</inf>–C), phosphorus (WS<inf>2</inf>–P), oxygen (WS<inf>2</inf>–O), and silicon (WS<inf>2</inf>–Si). These modifications significantly improved the material’s sensitivity and selectivity toward the targeted PTEs. Beyond atmospheric detection, the doped WS<inf>2</inf>sensor systems demonstrated strong potential for application in aqueous environments, indicating their suitability for water purification. The sensing capabilities of WS<inf>2</inf>were further substantiated by measurable alterations in electronic and charge transfer characteristics, as revealed through analyses of the density of states, work function, electrostatic potential profiles, and Bader charge analysis. To enable quantitative detection of PTEs under varying pressure, temperature, and surface coverage conditions, a statistical thermodynamics framework based on the Langmuir adsorption model was applied. Additionally, selective detection of PTEs was evaluated using nonequilibrium Green’s Functions (NEGF) formalism. Collectively, these findings highlight WS<inf>2</inf>-based nanosensors as a promising platform for the sensitive and selective adsorption and detection of toxic elements in diverse environmental settings.
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First-principles study insights into Janus MoWC-based MXenes for enhanced H2S and NH3 sensing applications
(2025-08-01)
Khammuang, Satchakorn
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Udomkijmongkol, Anan
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Thasitha, Sirinee
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Hussain, Tanveer
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Kotmool, Komsilp
Gas sensors are vital for environmental monitoring, industrial safety, and public health, enabling the detection of hazardous gases like H<inf>2</inf>S and NH<inf>3</inf>, even at low concentrations. This study uses first-principles calculations to investigate the gas-sensing properties of H<inf>2</inf>S and NH<inf>3</inf> gases on MoWC and MoWCO<inf>2</inf>, revealing key insights into their interaction mechanisms and potential for sensor applications. MoWC demonstrates stronger interactions with the gases compared to MoWCO<inf>2</inf>, as indicated by higher adsorption energy values. Charge transfer and electron density analysis suggest that the adsorption is primarily driven by charge exchange. The findings indicate that MoWC exhibits a highly sensitivity, undergoing significant work function changes when gas is adsorbed. However, AIMD results indicate that at 500 K, hydrogen atoms from gases attract to the surface and form terminal groups, making it unsuitable as a toxic gas sensor under these conditions. In contrast, MoWCO<inf>2</inf> exhibits too fast reversibility with an extremely short recovery time. In addition, we demonstrate that the sensing performance is enhanced by introducing O-vacancies in MoWCO<inf>2</inf>. The MoWCO<inf>2-vac</inf> shows increased adsorption energy for H<inf>2</inf>S and offers appropriate recovery times of 0.330 s with a sensitivity of 7.547 %, making it a suitable candidate for efficient room-temperature sensors. These findings pave the way to improve the potential of Janus MoWC-based MXenes for advanced H<inf>2</inf>S and NH<inf>3</inf> sensing applications.
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Smart Sensing Characteristics of Tungsten Diselenide (WSe2) Monolayers toward Depression-Related Volatile Organic Compounds
(2025-03-21)
Panigrahi, Puspamitra
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Kotmool, Komsilp
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Khammuang, Satchakorn
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Bae, Hyeonhu
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Gulati, Vandana
In this study, we designed efficient nanobiosensors based on two-dimensional tungsten diselenide (WSe<inf>2</inf>) monolayers to detect specific volatile organic compounds (VOCs) related to depression, such as butyric acid, furan, N-butylamine, and trimethylamine. First-principles calculations based on density functional theory revealed weak adsorption energies (E<inf>ads</inf>) on pristine (WSe<inf>2</inf>) and single Se-vacancy-induced (V<inf>Se</inf>-WSe<inf>2</inf>) monolayers. However, doping single atoms of Co, Fe, and Ni in WSe<inf>2</inf> at small concentrations of 1.33% not only improved the E<inf>ads</inf> values but also altered the electronic structures, which are essential for efficient sensing applications. Among the doped systems, Fe@WSe<inf>2</inf> showed tremendous improvement in its adsorption mechanism. Bader charge analysis, electrostatic potential, and work function calculations further validated the VOC sensing capabilities of the single-atom-dispersed WSe<inf>2</inf> monolayers. Additionally, the detection of VOCs under varying temperature and pressure conditions was investigated by using statistical thermodynamic analysis based on the Langmuir adsorption model.
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Single atom dispersed tungsten disulfide (WS2) based nanosensors for VOCs detection related to decomposed humans in disaster events
(2024-05-01)
Ueland, Maiken
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Bae, Hyeonhu
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Udomkijmongkol, Anan
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Kotmool, Komsilp
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Gulati, Vandana
Locating and recovering the victims as a result of disaster events is extremely challenging due to vast search areas, hazardous nature of destroyed infrastructure, and large number of potential victims. An effective avenue for the victim's detection is through the sensing of human-specific volatile organic compounds (VOCs) emitted both in life and in death. Motivated by this, we employed first principles density functional theory (DFT) calculations to study the sensing properties of pristine, vacancy-induced and single atom dispersed tungsten disulfide (WS<inf>2</inf>) monolayers towards 11 specific VOCs associated with decomposing humans. We found that pristine, and vacancy-induced WS<inf>2</inf> weakly adsorbed the selected VOCs with adsorption energies (E<inf>ads</inf>) between −0.26 to −0.76 eV. However, the incorporation of selected single atoms of Co, Fe, Nb, and Ni in WS<inf>2</inf> improved the sensing properties tremendously. In particular, Nb-WS<inf>2</inf> adsorbed the incident VOCs with E<inf>ads</inf> values of −1.89, −209, −1.43, −0.94, −2.08, −1.57, −1.44, −1.47, −1.70, −1.03, and −2.14 eV for 2-Butanone, benzaldehyde, butanol, heptane, hexanal, methylamine, dimethyl disulfide, dimethyl trisulfide, pyridine, octane, and toluene, respectively, which are ideal for efficient sensing mechanism. Appropriate adsorptions were coupled with the measurable changes in the electronic properties (band gaps) of Nb-WS<inf>2</inf>, which is essential for proficient sensing. Charge transfer analysis, electro localization functions, electrostatic potentials, and work function calculations further authenticated the sensing propensities of single atom dispersed WS<inf>2</inf>. Finally, Langmuir adsorption model was employed to explore the sensing at diverse pressure and temperature settings. We believe that these results will help for the development of highly efficient nanosensors for the detection of VOCs related to decomposed humans in mass disaster events. This will increase the detection ability and the chance of locating these victims.

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