Strain engineering tuned vibrational dynamics of 2D transition metal dichalcogenide heterostructures: A first-principles investigation.

Controlling vibrational modes and energy gap by creating van der Waals (vdW) heterostructures through strain engineering is a novel approach to tailor the vibrational and electronic properties of two-dimensional (2D) materials. Numerous theoretical and experimental studies have significantly contributed to analysing the properties of transition metal dichalcogenides (TMDs), known for their multifunctional applications. In this study, we investigate the strain and stacking dependent vibrational properties of WSe2/MoSe2 and MoSe2/WSe2/MoSe2 vdW heterostructures using first-principles based density functional theory calculations.

Metal-Metalloid Modified C Fullerene: A Dual Role in Drug Delivery and Sensing for Anticancer Chlormethine Explored through DFT and MD Simulations.

Spurred by the latest developments and growing utilization of zero-dimensional (0D) drug delivery and drug sensors, this investigation examines the possibilities of the 0D C fullerene for drug delivery and the detection of the anticancer drug chlormethine (CHL), the overabundance of which poses a significant threat to living organisms. This study employs density functional theory and ab initio molecular dynamics (AIMD) simulations (AIMD) to evaluate and gain insights into the interaction mechanisms between pristine C fullerene, metal-metalloid (MM)-modified C fullerene (with Al, Fe, and B), and the anticancer drug CHL. It is observed that in the gas phase, the CHL drug molecule adsorbs onto the fullerenes in the following order: B-C > Fe-C > Al-C > C.

Topological signatures of triply degenerate fermions in Heusler alloys: anstudy.

Triply degenerate nodal point (TP) fermions, lacking elementary particle counterparts, have been theoretically anticipated as quasiparticle excitations near specific band crossing points constrained by distinct space-group symmetries instead of Lorentz invariance. Here, based oncalculations and symmetry analysis, we demonstrate the presence of TP fermions in Heusler alloys. Furthermore, we predict that these Heusler alloys are dynamically stable, exhibiting TP fermions along four distinctaxes in the F-43m space group.

Exploration of Si-N compounds as high energy density materials.

The non-molecular phases of polymeric nitrogen formed under high pressure have potential applications in the area of high energy density materials (HEDMs). Herein, we explored silicon-based nitride materials using a structural search algorithm combined with first-principles calculations. We predicted new phases of SiN that are identified to be metastable together with the previously reported stable compositions of SiN and SiN.

Size-Dependent Fullerenes for Enhanced Interaction of l-Leucine: A Combined DFT and MD Simulations Approach.

Fullerene-based biosensors have received great attention due to their unique electronic properties that allow them to transduce electrical signals by accepting electrons from amino acids. Babies with MSUD (maple syrup urine disease) are unable to break down amino acids such as l-leucine, and excess levels of the l-leucine are harmful. Therefore, sensing of l-leucine is foremost required.

Non-trivial topological phases in transition metal rich half-Heusler oxides.

Topological insulators with gapless surface states and insulating bulk in non-centrosymmetric cubic systems have been extensively explored following the discovery of two-dimensional quantum spin hall effect in zincblende HgTe. In such systems the negative band inversion strength EBIS(= EΓ6-EΓ8<0) governs the robustness of the non-trivial topological states at ambient conditions. Hence, realizing large negative values of EBIShas been a guiding motivation of several investigations reported in literature.

DFT stimulation and experimental insights of chiral Cu(II)-salen scaffold within the pocket of MWW-zeolite and its catalytic study.

A Cu(II)-salen complex encapsulated in MWW-framework as an efficient chiral organocatalyst was developed for the synthesis of 3,4-dihydropyrimidin-2-(1)-one (DHPMs) derivatives an asymmetric pathway. In order to confirm its structural properties, single-crystal X-ray diffraction, powder XRD, BET, XPS, FE-SEM, EDX, UV-Vis, and FTIR spectra were used. Using computer-assisted DFT calculations, the Cu(II)-salen complex has been fine-tuned to fit into the pocket of the porous MWW support while keeping its chirality.

Site-selective unidirectional benzylic sp C-H oxidation of dodecahydrotriphenylene with RuCl-NaIO: formation of benzylic ketones.

Dodecahydrotriphenylene, a higher homologue of trindane chemoselectively undergoes unidirectional benzylic sp C-H oxidation and the central benzene ring remains intact unlike that in trindane under similar reaction conditions. RuO which generally attacks sp C-H to form oxidative products is found to give benzylic ketones sp C-H oxidation. Density functional theory (DFT) calculations have also been performed to analyse the potential energy, energy barrier and HOMO-LUMO energy gap of the products.

Functionalized tellurene; a candidate large-gap 2D topological insulator.

The discovery of group IV and V elemental xene's with topologically non-trivial characters in their honeycomb lattice structure (HLS) has led to extensive efforts in realising analogous behaviour in group VI elemental monolayers. Theoretically; it was concluded that, group VI elemental monolayers cannot exist in HLS. However, some recent experimental evidence suggests that group VI elemental monolayers can be realised in HLS.

Dressing of Cu Atom over Nickel Cluster Stimulating the Poisoning-Free CO Oxidation: An Ab Initio Study.

In this work using first-principles calculations based on spin-polarized density functional theory (DFT), the role of the Cu atom in degrading the poisoning of carbon monoxide (CO) over NiCu clusters is unveiled. The search has been initiated with the examination of structural, magnetic, and electronic properties of Ni and NiCu clusters (1 ≤ ≤ 12). X-ray absorption near-edge structure (XANES) spectra of Ni K-edge are computed to extract the information on the oxidation states and coordination environment of metal sites of the clusters.

Superior Room-Temperature Ammonia Sensing Using a Hydrothermally Synthesized MoS/SnO Composite.

Layered two-dimensional transition metal dichalcogenides, due to their semiconducting nature and large surface-to-volume ratio, have created their own niche in the field of gas sensing. Their large recovery time and accompanied incomplete recovery result in inferior sensing properties. Here, we report a composite-based strategy to overcome these issues.

Dimensional engineering of a topological insulating phase in Half-Heusler LiMgAs.

We propose a novel technique of dimensional engineering to realize low dimensional topological insulator from a trivial three dimensional parent. This is achieved by confining the bulk system to one dimension along a particular crystal direction, thus enhancing the quantum confinement effects in the system. We investigate this mechanism in the Half-Heusler compound LiMgAs with face-centered cubic (FCC) structure.

Emergence of -, --band inversion in zincblende gold iodide topological insulator and its thermoelectric properties.

We employcalculations to investigate the topological states (TS) and thermoelectric (TE) transport properties of three dimensional (3D) gold iodide (AuI) which belongs to the zincblende family. We explore, semi-metal (SM) to topological conductor (TC) and topological insulator (TI) phase transitions. Under pristine conditions, AuI exhibits Dirac SM nature but, under the influence of mild isotropic compressive pressure the system undergoes electronic quantum phase transition driving it into non-trivial topological state.

Highly sensitive and flexible pressure sensor based on two-dimensional MoSe nanosheets for online wrist pulse monitoring.

The advancement of portable and flexible electronics that is integrated with multiple sensing functions has increasingly drawn considerable interest. The fabricated sensors would have the ability to sense multiple deformations like pressing, twisting and trivial vibrations such as pulses of wrist vibrations to mimic human skin. Presently, we implemented an easy, cost-effective and optimized fabrication technique for production of pressure sensors based on MoSe nanosheets coated on cellulose paper.

Electron density modulation of a metallic GeSb monolayer by pnictogen doping for excellent hydrogen evolution.

The catalyst assisted water-splitting method as an eco-friendly and cleaner pathway for energy generation has gained much interest in recent times. In this regard, numerous two-dimensional electrocatalysts such as mono/binary compounds synthesized from group IV, III-V and V elements with compatible activity towards hydrogen evolution, oxygen evolution, oxygen reduction and CO reduction have been reported. Motivated by the novel approach of material design and the need for better and cheaper electrocatalytic materials, we have investigated the ground state properties of the GeSb monolayer using state-of-the-art density functional theory.

Influence of surface oxygen clusters upon molecular stacking of paclitaxel over graphene oxide sheets.

Aqueous dispersibility of graphene oxide (GO) sheets can be improved through enrichment of oxygen content (oxidation). However, the resulting 'oxygen clusters' are accompanied with numerous point defects, depletive to π-π stacking behavior of sheets. In this work, we have investigated the properties of sheets oxidized with 2, 4, 6, 8, 10 and 12 weight equivalents of KMnO.

Unexpected persistence of cis-bridged chains in compressed AuF.

Raman scattering measurements indicate that cis-bridged chains are retained in AuF3 even at a compression of 45 GPa - in contrast to meta-GGA calculations suggesting that structures with such motifs are thermodynamically unstable above 4 GPa. This metastability implies that novel gold fluorides (e.g.

Colloidal stability of graphene oxide nanosheets in association with triblock copolymers: A neutron scattering analysis.

This study investigates stabilization of graphene oxide (GO) nanosheets in polyethylene oxide-polypropylene oxide (PEO-PPO) block copolymers (P103, P123 and F127). Changes in micellization of copolymers upon GO addition were monitored using dynamic light (DLS) and small angle neutron scattering (SANS). Structural developments at sheet surface were studied with two possibilities; (i) adsorption of PPO block over hydrophobic basal plane allowing the engagement of hydrophilic PEO with aqueous bulk, and (ii) adsorption of micelles mediated via carboxylated groups.

Volume expansive pressure (VEP) driven non-trivial topological phase transition in LiMgBi.

Topological Insulators (TI) exhibit robust spin-locked dissipationless Fermion transport along the surface states. In the current study, we use first-principles calculations to investigate a Topological Phase Transition (TPT) in a Half-Heusler (HH) compound LiMgBi driven by a Volume Expansive Pressure (VEP) which is attributed to the presence of, intrinsic voids, thermal perturbations and/or due to a phenomena known as cavity nuclei. We find that, the dynamically stable face-centred cubic (FCC) structure of LiMgBi (which belongs to the F4[combining macron]3m[216] space group), undergoes TPT beyond a critical VEP (at 4.

High-Pressure Phase Transitions of Zinc Difluoride up to 55 GPa.

Studying the effect of high pressure (exceeding 10 kbar) on the structure of solids allows us to gain deeper insight into the mechanism governing crystal structure stability. Here, we report a study on the high-pressure behavior of zinc difluoride (ZnF)-an archetypical ionic compound which at ambient pressure adopts the rutile (TiO) structure. Previous investigations, limited to a pressure of 15 GPa, revealed that this compound undergoes two pressure-induced phase transitions, i.

Uncovering the structural, electronic and vibrational properties of atomically precise PdCu clusters and their interaction with CO molecule.

In this work, we address the structural stability, electronic properties and effect of metal-metal interaction on Raman spectra of icosahedral (Ih) PdCu (m + n = 13) clusters using first principles calculations based on dispersion-corrected density functional theory (DFT-D2). Initially, we investigated the relative stability of Ih PdCu clusters over monometallic Ih Pd and Cu clusters by calculating the average binding energy per atom, mixing energy, second order energy difference and average bond length. The Ih PdCu is the most stable bimetallic cluster with the 2.

Slow degrading hyaluronic acid hydrogel reinforced with cationized graphene nanosheets.

Graphene possesses a large surface area and offers high loading capacity for aromatic compounds. However, the load is quickly released in the absence of rate limiting diffusion barrier. In this study, we have explored the electrostatic interaction between polyanionic hyaluronic acid (HA) and cationized reduced graphene oxide (rGO) as a means to develop a reinforced hydrogel matrix.

Halogenation of SiGe monolayers: robust changes in electronic and thermal transport.

Phonon and electronic transport of buckled structured SiGe monolayer and halogenated SiGe monolayers (X-SiGe, X = F, Cl, and Br) are investigated for the first-time using ab initio density functional theory (DFT). The phonon calculations reveal complete dynamical stability of SiGe and fluorinated (F-SiGe) monolayers in contrast to earlier reported works, where a small magnitude of imaginary frequency in SiGe monolayer near the zone centre of the Brillouin zone (BZ) is observed. The phonon calculations of chlorinated and brominated SiGe reveal no dynamical stability even with very high convergence parameters and better computational accuracy.