A phase-pure nanocrystalline ZnCuTiO4 spinel oxide was synthesized via the Pechini-type sol-gel method and investigated as a visible-light-driven photocatalyst for persulfate-assisted environmental remediation. Structural characterization and phase purity of the cubic spinel lattice were thoroughly established through X-ray diffraction, Fourier-transform infrared spectroscopy, Transmission electron microscopy and Raman spectroscopy. The optical bandgap was determined to be 2.5 eV by UV-visible diffuse reflectance spectroscopy, and Mott-Schottky measurements confirmed n-type semiconducting behavior. First-principles study, based on A DFT + U investigation was conducted to further explore the electronic properties of ZnCuTiO4, suggesting a cubic n-type semiconductor with a direct bandgap, where strong Ti and O orbital hybridization and metal oxygen covalency governs its electronic structure. Under solar-light irradiation in the presence of peroxydisulfate, ZnCuTiO4 achieved complete degradation of methylene blue within 30 min and provided broad-spectrum efficacy for removal of diverse organic pollutants. Reactive species trapping experiments established that the photocatalytic mechanism proceeds through simultaneous radical (SO4-center dot, (OH)-O-center dot) and non-radical oxidation pathways, attributed to the synergistic activation of peroxydisulfate at the semiconductor surface. These findings establish the structure-electronic property and solar photocatalytic response of ZnCuTiO4, offering a platform for the rational design of trimetallic spinel oxides for solar-driven water remediation.

In this work, Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations are utilized to study the hydrogen storage potential of a hexagonal boron nitride (h-BN) monolayer doped with a Scandium (Sc) atom. Sc occupies the boron site of h-BN with a strong binding energy of -6.8 eV, while a high diffusion barrier limits dopant mobility and inhibits clustering. Also, MD simulation at 300 K confirms the system's thermal stability, and a positive phonon dispersion indicates dynamical stability. By reducing its bandgap from 4.61 to 1.87 eV and introducing new states close to the Fermi level that act as active adsorption sites for H2 molecules, Sc doping significantly changes the electronic properties of pristine h-BN. Among the adsorption sites considered, the nitrogen site was found to be the most favorable, exhibiting an adsorption energy of -0.34 eV. The Sc-doped h-BN monolayer could hold up to 9H2 molecules, achieving a maximum theoretical gravimetric density of 6.58 wt.%. Furthermore, thermodynamic modelling under realistic conditions (30 atm, 25 degrees C for adsorption and 3atm, 100 degrees C for desorption) yields a usable capacity of 4.62 wt.%. These results highlight Sc-doped h-BN monolayers as a stable and efficient reversible hydrogen storage material suitable for clean energy applications.

The Early screening of volatile organic compounds (VOCs) linked to lung cancer (LC) is essential for advancing non-invasive diagnostic methods. This work employs Density Functional Theory (DFT) incorporating Grimme's DFT-D3 dispersion corrections, to study the adsorption and sensing characteristics of pristine and Ag-doped PdSe2 monolayers toward four LC-related VOC biomarkers: isoprene (C5H8), acrolein (C3H4O), isobutyraldehyde (C4H8O), and propan-1-ol (C3H8O). Pristine PdSe2 exhibits a 1.20 eV bandgap and strong Pd-Se orbital hybridization, while Ag substitution at Se sites reduces the bandgap to 0.68 eV, introducing localized states that enhance electrical responsiveness. Adsorption studies reveal strong affinities (-1.33 to -1.72 eV), moderate charge transfer (-0.01 to -0.13 e), and adsorption distances of similar to 2.2-2.3 & Aring;. Notably, C5H8 induces a significant bandgap modulation (0.68 to 0.79 eV), highlighting its strong sensing response. Ab initio molecular dynamics (AIMD) simulations at 300 K confirm the thermal stability of both pristine and Ag-PdSe2 monolayers. Work function (WF) analysis indicates that C5H8, C4H8O, and C3H8O reduce the WF, enhancing electron emission, while C3H4O slightly increases it, hindering transport. Current-voltage (IV) characteristics demonstrate selective detection, with C5H8 (74.4 %) and C3H8O (70.38 %) exhibiting the highest sensitivities at 1.5 V bias, whereas C3H4O and C4H8O remain below 40 %. These findings establish Ag-PdSe2 as a robust and selective 2D material platform for Field Effect Transistor (FET)-type chemiresistive sensors, offering significant potential for non-invasive lung cancer diagnosis.

Driven by the need to protect biological life, the development of high-performance sensors for the early detection of environmental toxic gases has become a global research priority. In this study, under the framework of Density Functional Theory (DFT), the adsorption and sensing mechanism of scandium-doped MoS2 (Sc-MoS2) monolayer toward environmental toxic gases (CO, CO2, NO, NO2, SO2, SO3, and NH3) has been investigated. The calculated binding energy (Eb) of-5.52 eV confirmed the structural stability of Sc-MoS2 monolayer. The Ab Initio Molecular Dynamic (AIMD) simulations at 300, 400 and 500 K confirmed thermal stability of the Sc-MoS2. The bandgap (Eg) of MoS2 intensely decreased to 0.17 eV from 1.62 eV after suitable Sc-doping on S vacancy site of MoS2 surface, driven by the introduction of Sc-3d impurity states near the Fermi level. The toxic gases adsorbed system on Sc-MoS2 has the strong chemisorption with adsorption energy (Ead) ranging from-1.17 eV for CO2 to a maximum of-3.57 eV for NO2. The distinct redshift in the adsorption spectra and noteworthy variation in the static dielectric constant was confirmed by the optical property analysis. The Current Voltage (IV) characteristics computed using Non-Equilibrium Green's Function (NEGF) showed a non-ohmic behaviour. The sensing performance showed a distinct sensitivity of 93.84% for CO2 and 87.55% for CO at an applied bias of 1.15 eV. The finding suggests that Sc-MoS2 sensor platform acts as a high sensitivity toward the target gas at 300 K due to strong recovery time (tau), while the sensor achieves short recovery time at 500 K, with tau for CO2 dropping to 0.58 s. This comprehensive investigation suggests Sc-MoS2 as a potential and promising 2D platform for Field Effect Transistor (FET)-type chemiresistive sensors for selective detection of environmental toxic gases.

Solid-state hydrogen storage materials with tunable properties are crucial for developing sustainable energy systems. In this work, we have investigated the structural, electrical, thermal, and adsorption–desorption properties of scandium (Sc)- and hafnium (Hf)-decorated MoS2 monolayers using density functional theory (DFT) and molecular dynamics (MD) simulations to evaluate their potential as a hydrogen storing medium. Both dopants preferentially occupy the hollow sites with strong binding energy of 3.56 eV and 4.21 eV; however, the high diffusion energy barrier of Sc and Hf atoms suppresses the clustering effect. The positive phonon spectrum and stable MD results at 300, 500, and 700 K confirm the dynamic and thermal stability of the decorated systems. Sc and Hf decoration substantially modify the electronic property of MoS2 by introducing a new energy state near the Fermi level, enabling stronger interaction with hydrogen. Sc-MoS2 exhibits a semiconductor-to-metallic transition at low H2 coverage, whereas Hf-decorated MoS2 retains its semiconducting nature even after adsorption. The decorated systems can hold up to eight H2 molecules (Sc-MoS2) with adsorption energy ranging from −0.48 eV to −0.24 eV per H2 molecule, while Hf-MoS2 can bind up to seven molecules, having adsorption energy in the range of −0.84 eV to −0.28 eV/H2. Although the resulting gravimetric density is still below the DOE target, these adsorption energies are within the range for reversible hydrogen adsorption. MD simulations further verify the thermal stability of maximum H2-loaded systems performed at different temperatures. Overall, the results highlight the effectiveness of transition metal decoration in tailoring the hydrogen adsorption and desorption behaviour of MoS2, guiding the design of next-generation 2D hydrogen storage materials.

Magnesium ion batteries (MIBs) have attracted much attention as an affordable alternative to lithium-ion batteries (LIBs) due to the growing demand for energy storage devices. This study employs density functional theory (DFT) to examine the viability of vanadium-decorated $\mathbf{WS}_{\mathbf{2}}$ (V-WS2) monolayer as an anode material for magnesium-ion batteries (MIBs). The structural, electrical, and electrochemical properties are examined through the adsorption of two Mg atoms. The key parameters, including adsorption energy ($\mathbf{E}_{\text{ad }}$), formation energy ($\mathrm{E}_{f}$), open-circuit voltage, and maximum theoretical capacity, are calculated to assess the interaction between $\text{WS}_{2}$ and $\mathrm{V}-\text{WS}_{2}$ surface. A significant decrease in the bandgap was observed, indicating a change from semiconducting to metallic behavior, thereby resulting in increased conductivity of the material. The enhanced metallicity was further confirmed by the density of states (DOS) and partial density of states (PDOS) at higher Mg concentrations. The maximum theoretical capacity of $154.24 \text{mAh} / \mathrm{g}$ and an average OCV of 1.02 V highlight the promising electrochemical performance of the optimized structure with two adsorbed Mg atoms $\left(\text{Mg}_{2} \text{WS}_{2}\right)$. These results imply that $\mathrm{V}-\text{WS}_{2}$ is a viable anode material for MIBs with robust energy storage applications and tunable electronic properties.

Two-dimensional materials such as MoS2 have garnered considerable attention as possible anode candidates for next-generation sodium-ion batteries (NIBs), to satisfy the growing need for energy storage devices. In this study, density functional theory (DFT) is used to examine the potential of MoS2 as an anode material for NIBs. Ab initio molecular dynamics (AIMD) simulations verified the thermal and dynamic stability of pristine MoS2, demonstrating structural stability in the range of 300–400 K. It was determined that the maximum adsorption energy (Ead) for the adsorption of eight Na atoms is −12.74 eV. Furthermore, the exothermic adsorption process is confirmed by the formation energy (Ef) of −5.70 eV for eight Na atoms on the MoS2 monolayer. When a single Na atom is adsorbed, the electronic band structure of pristine MoS2 rises slightly from 1.73 to 1.75 eV. However, the bandgap shrinks and eventually disappears upon the adsorption of two Na atoms, signifying a shift to metallic behaviour and enhanced electronic conductivity. Its potential for large-scale energy storage devices is further highlighted by its high theoretical capacity of 1339 mAh g−1. The estimated average open-circuit voltage (OCV) of 1.59 V confirms that Na-MoS2 is a suitable anode material for NIBs. Furthermore, a diffusion barrier of 0.8 eV indicates moderate Na-ion mobility, which is advantageous for real-world battery applications. Overall, MoS2 is a good option for next-generation NIB technology due to its strong Na–MoS2 interaction and tunable electronic properties. Therefore, this work lays the groundwork for future research and development of MoS2-based anode materials.

In this study, the adsorption properties of three byproducts of sulfur hexafluoride (SF6) decomposition gases on a 1T-HfTe2 monolayer were investigated within the framework of Density Functional Theory (DFT). SF6 is commonly used in high-voltage transformers as an arc-extinguishing and insulating medium. The Perdew–Burke–Ernzerhof (PBE) functional within the Generalized Gradient Approximation (GGA) was employed for the computational analysis. Adsorption energy ( ), charge transfer ( ), band gap, density of states (DOS), and recovery time ( ) were calculated to understand the adsorption mechanisms of HfTe2 monolayers toward SF6 decomposition products. The results revealed that the adsorption of SOF2, SO2, and SO2F2 exhibits chemisorption, with adsorption energies of –0.41, –0.39, and –0.30 eV, respectively. Among these, SOF2 showed the strongest interaction, while SO2F2 exhibited the weakest. The HfTe2 monolayer demonstrated favorable and rapid recovery times, calculated to be 0.14 µs for SOF2 and 4 µs for SO2. These findings provide a foundation for the development of 1T-HfTe2-based sensors and adsorbents for use in SF6-insulated electrical equipment.

This paper investigates the optical, electronic, and magnetic properties of Fe, Co, and Cu-doped Boron Nitride Nanotubes (BNNTs) using density functional theory (DFT) model. BNNTs possess stable bandgaps of 3.5 eV with insulating behaviour and good structural stability. The bandgap narrows when doped with transition metals (TMs) and most system showed direct bandgap predicting their optoelectronic applications. There is a shift in bandgap with an additional formation of new electronic states near the fermi level for doped BNNT. Attributing to the contribution from 4d orbitals of TMs dopant, predicting high electron mobility and faster electron injection for sensors use. Magnetic analysis revealed a significantly increase in ferromagnetism in Fe, Co, and Cu-doped BNNTs. Amongst, Fe doping shows the strongest magnetic moments while Co and Cu doping introduces both ferromagnetic and antiferromagnetic traits. Optical analysis indicates that doped BNNTs exhibit an increased dielectric constants, refractive index, and absorption characteristics particularly in the ZZ plane. TMs-doped BNNTs show higher extinction coefficients and distinct absorption peaks due to the creation of new electronic states at the fermi level with higher degree of scattering. These modifications in the electronic structure enhance the ability of BNNTs to absorb light more effectively at certain wavelengths suggesting their effectiveness in radiation absorption and filtering. Advanced synthesis methods and ongoing research are important to fully exploit BNNTs implementation in future technologies.

Lung cancer (LC) is still among the most fatal cancers, in large part because of the difficulty of early detection. The present work explores a silicon-functionalized tungsten diselenide monolayer (Si-WSe2) as a potential biosensing platform for non-invasive VOC detection with LC biomarkers. Using density functional theory (DFT) in generalized gradient approximation (GGA), we critically examine the impact of silicon doping on the electronic characteristics of WSe2. Parameters such as binding energy, adsorption energy, charge transfer, density of states (DOS), and sensitivity are computed for C3H4O, C5H8, and C3H8O. Our results show that Si-doping not only lowers the bandgap significantly (from 1.5 eV to 0.53 eV) but also enhances adsorption properties, with C5H8 and C3H4O displaying strong chemisorption (adsorption energies of -1.97 eV and -1.80 eV, respectively) compared to physisorption C3H8O (-0.80 eV). The DOS and projected DOS (PDOS) variations corroborate extensive charge redistribution and orbital hybridization at the Fermi level, in agreement with the observed high sensitivity, particularly for C3H4O (99.95 %). These results substantiate the viability of Si-WSe2 in the construction of rapid, sensitive, and selective breath-based diagnostic devices for the early diagnosis of LC.

Magnetic skyrmion has great potential as information carriers in next-generation logic, neuromorphic computing, and memory devices because of its topological stability, incredibly compact size, and low current consumption required to operate it. In this work, the computational demonstration of a skyrmion controlled by a voltage controlled magnetic anisotropy (VCMA) gradient on a trapezoidal nanotrack is studied for the application of racetrack memory. The trapezoidal nanotrack aids in guiding the skyrmion's motion under the anisotropy gradient by leveraging the edge repulsion force. By utilizing a defect, the proposed device ensures a continuous flow of binary bits ‘0’ and ‘1’ without any accumulation on the racetrack. The higher angle (θhigh) and higher anisotropy gradient (ΔKu-high) of the trapezoidal nanotrack accelerates the skyrmion owing to higher edge repulsion force and energy gradient force. The maximum speed of 1.27 m/s was achieved by the skyrmion, and the minimum time taken for the skyrmion to reach the detector from the nucleation point was 2.16 ns. The energy used to maintain the electric field is 4.58fJ per bit operation. This presents a novel approach to manipulate skyrmions under anisotropy gradient (ΔKu) on the trapezoidal nanotrack, paving the way for the development of improved skyrmion racetrack memory (sk-RM).

The magnetic skyrmion is a promising information carrier for next generation logic, neuromorphic computing, and memory devices due to its topological stability, extremely small size, and low operating current. A computational demonstration of a skyrmion driven on a synthetic antiferromagnet nanotrack using a voltage controlled magnetic anisotropy gradient for the application of racetrack memory device is studied in this work. The velocity of the skyrmion is dependent on Gilbert damping constant. The proposed device makes use of the notch at the end of the nanotrack ensuring a constant flow of ‘0’ and ‘1’ bits without any accumulation on the racetrack.

Novel MTJs structure comprising of LDMs (MgO, Al2O3, h-BN and HfO2) as tunnel layer sandwiched between Fe as ferromagnetic (FM) layer is designed for novel magnetic random access memory (MRAM) application. MTJLab Tool with inbuilt non-equilibrium Green’s function (NEGF) model avails in calculating the spin transfer torque (STT) property of MTJs device. As STT define the critical parameters such as switching current density, thermal stability, torque asymmetry and reliability of MTJs. Amongst, HfO2 and h-BN device showed the highest difference in STT components i.e., 1 mA and 0.8 mA along with higher number of stable and accessible memory states. Hence, they are considered as an ideal candidate for implementation as tunnel layer in advance MTJs device.

The investigation of respired breath was done to examine the potential of the P- doped WSe2 (P-WSe2) monolayer for identifying biomarkers associated with lung cancer (LC). The geometric adsorption, and electronic characteristics of the P-WSe2 monolayer, for three Volatile Organic Compounds (VOCs), namely, 2-propenal (C3H4O), propanal (C3H6O), and isoprene (C5H8) are investigated based on the Density Functional Theory (DFT). The Adsorption Energy (Ead) was calculated to be -0.6 eV, -0.57 eV and -1.31 eV for C3H4O, C3H6O, and C5H8 gas, respectively. The Density of States (DOS), binding energy, charge transfer, and desorption time at temperatures 298 K, 348 K and 398 K have been reported in this work.

Under the framework of density functional theory (DFT), computational analysis of Fe-doped ZnO as a sensing material has been presented in this paper. The electronic and adsorption properties, including charge transfer, density of states, adsorption energy, band structure, and recovery time, have been studied. The electrical activity of Fe-doped ZnO for the adsorption of H2S and NO2 gases has been studied. Fe–ZnO (replaced O) and Fe–ZnO (replaced Zn) were determined to have a binding energy of − 2.2 eV and − 2.6 eV, respectively, indicating that the Zn-atom replaced by the Fe atom exhibited a more stable structure. The adsorption energy for NO2 gas (− 2.72 eV) was better than that of H2S gas (− 0.55 eV). This means that the material is more effective in adsorbing NO2 gas than H2S gas. The recovery time, or the time the material took to return to its initial state after adsorption was also investigated with different temperatures for H2S–Fe–ZnO and NO2–Fe–ZnO. The band gap of 2.47 eV, 1.28 eV, 0.83 eV and 1.94 eV was calculated for ZnO, Fe–ZnO, H2S–Fe–ZnO, and NO2–Fe–ZnO, respectively. The results suggested that the material has potential for use in H2S gas sensing applications.

This paper presents a computational study investigating the potential of MoS2 and C-doped MoS2 monolayers as breath sensors for detecting Volatile Organic Compounds (VOCs) associated with lung cancer (LC). The sensing characteristics of MoS2 and C-MoS2 towards LC-related VOCs were explored using Density Functional Theory (DFT) calculations. The exchange-correlation energy was calculated using the Generalized Gradient Approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) functional. Our finding showed VOCs associated with LC such as C3H4O, C4H8O, C5H8, and C6H12 interacted with the MoS2 monolayer, with adsorption energies − 0.80 eV, -0.82 eV, -1.01 eV, and − 0.99 eV, respectively. However, the interaction is greatly enhanced by C-doped MoS2 with adsorption energies − 2.04 eV, -2.12 eV, -1.85 eV, and − 2.25 eV, respectively for C3H4O, C4H8O, C5H8 and C6H12. Additionally, we investigated the impact of gas adsorption on the bandgap of the materials to assess their electrical variations. Pristine MoS2 exhibited minimal changes in bandgap upon VOC adsorption. In contrast, C-MoS2 displayed a remarkable increase in bandgap, ranging from 0.71 eV to 1.56 eV, compared to its initial value of 0.69 eV. This significant increase indicates an improved sensitivity of C-MoS2 as a breath sensor for LC-related VOCs. Furthermore, we reported structural variations, density of states (DOS), charge transfer, work function, and recovery time analysis. Our results demonstrate that C-MoS2 exhibits promising characteristics for detecting VOCs associated with LC.

In this work we investigated the performance of Single-Walled Boron Nitride Nanotube (SWBNNT) sandwiched between CrO2 based Magnetic Tunnel Junction (MTJ) structures with atomistic simulations. MTJ based device-level simulation was performed using the Extended Huckel based Tight Binding (EHTB) model. The SWBNNT as a dielectric layer and CrO2 as Ferromagnetic (FM) layers based Magnetic Tunnel Junction (MTJ) heterostructure was computed. The proposed MTJ device operates at the nano-Ampere (nA) range depicting its potential application in a low-powered nanoelectronics device. It also shows a promising Tunnel Magnetoresistance (TMR) effect. The practical circuit-level implementation of the proposed MTJ device in Magnetic Random-Access Memory (MRAM) was validated using LTspice. Hence, the calculated static power consumption and writing energy per bit was minimal for S1 and S2 based MRAM circuit. The perfect switching operation was depicted by the proposed MTJ device based MRAM.