Enhancement of superconductivity in Zr2S2C arising from phonon softening on transition from bulk to monolayer.

We report a new compound, Zr2S2C, belonging to the transition metal carbo-chalcogenide (TMCC) family. Through first-principles calculations, our analysis of phonon dispersion spectra indicates that the compound is dynamically stable in both bulk and monolayer forms. We systematically investigated the electronic structure, phonon dispersion, and electron-phonon coupling (EPC) driven superconducting properties in bulk and monolayer Zr2S2C. The results demonstrate the metallic character of bulk Zr2S2C, with a weak EPC strength (λ) of 0.41 and superconducting critical temperature (Tc) of ∼3 K. The monolayer Zr2S2C has an enhancedλof 0.62 andTcof ∼6.4 K. The increasedλvalue in the monolayer results from the softening of the acoustic phonon mode. We found that when biaxial strain is applied, the low energy acoustic phonon mode in monolayer becomes even softer. This softening leads to a transformation of the Zr2S2C monolayer from its initial weak coupling state (λ= 0.62) to a strongly coupled state, resulting in an increasedλvalue of 1.33. Consequently, the superconducting critical temperature experiences a twofold increase. These findings provide a theoretical framework for further exploration of the layered two-dimensional TMCC family, in addition to offering valuable insights.

Interventions for postburn pruritus.

BACKGROUND: Postburn pruritus (itch) is a common and distressing symptom experienced on healing or healed burn or donor site wounds. Topical, systemic, and physical treatments are available to control postburn pruritus; however, it remains unclear how effective these are. OBJECTIVES: To assess the effects of interventions for treating postburn pruritus in any care setting. SEARCH METHODS: In September 2022, we searched the Cochrane Wounds Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (including In-Process & Other Non-Indexed Citations), Ovid Embase, and EBSCO CINAHL Plus. We also searched clinical trials registries and scanned references of relevant publications to identify eligible trials. There were no restrictions with respect to language, publication date, or study setting. SELECTION CRITERIA: Randomised controlled trials (RCTs) that enrolled people with postburn pruritus to compare an intervention for postburn pruritus with any other intervention, placebo or sham intervention, or no intervention. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by Cochrane. We used GRADE to assess the certainty of the evidence. MAIN RESULTS: We included 25 RCTs assessing 21 interventions with 1166 randomised participants. These 21 interventions can be grouped into six categories: neuromodulatory agents (such as doxepin, gabapentin, pregabalin, ondansetron), topical therapies (such as CQ-01 hydrogel, silicone gel, enalapril ointment, Provase moisturiser, beeswax and herbal oil cream), physical modalities (such as massage therapy, therapeutic touch, extracorporeal shock wave therapy, enhanced education about silicone gel sheeting), laser scar revision (pulsed dye laser, pulsed high-intensity laser, fractional CO2 laser), electrical stimulation (transcutaneous electrical nerve stimulation, transcranial direct current stimulation), and other therapies (cetirizine/cimetidine combination, lemon balm tea). Most RCTs were conducted at academic hospitals and were at a high risk of performance, attrition, and detection bias. While 24 out of 25 included studies reported change in burn-related pruritus, secondary outcomes such as cost-effectiveness, pain, patient perception, wound healing, and participant health-related quality of life were not reported or were reported incompletely. Neuromodulatory agents versus antihistamines or placebo There is low-certainty evidence that doxepin cream may reduce burn-related pruritus compared with oral antihistamine (mean difference (MD) -2.60 on a 0 to 10 visual analogue scale (VAS), 95% confidence interval (CI) -3.79 to -1.42; 2 studies, 49 participants). A change of 2 points represents a minimal clinically important difference (MCID). Due to very low-certainty evidence, it is uncertain whether doxepin cream impacts the incidence of somnolence as an adverse event compared to oral antihistamine (risk ratio (RR) 0.64, 95% CI 0.32 to 1.25; 1 study, 24 participants). No data were reported on pain in the included study. There is low-certainty evidence that gabapentin may reduce burn-related pruritus compared with cetirizine (MD -2.40 VAS, 95% CI -4.14 to -0.66; 1 study, 40 participants). A change of 2 points represents a MCID. There is low-certainty evidence that gabapentin reduces the incidence of somnolence compared to cetirizine (RR 0.02, 95% CI 0.00 to 0.38; 1 study, 40 participants). No data were reported on pain in the included study. There is low-certainty evidence that pregabalin may result in a reduction in burn-related pruritus intensity compared with cetirizine with pheniramine maleate (MD -0.80 VAS, 95% CI -1.24 to -0.36; 1 study, 40 participants). A change of 2 points represents a MCID. There is low-certainty evidence that pregabalin reduces the incidence of somnolence compared to cetirizine (RR 0.04, 95% CI 0.00 to 0.69; 1 study, 40 participants). No data were reported on pain in the included study. There is moderate-certainty evidence that ondansetron probably results in a reduction in burn-related pruritus intensity compared with diphenhydramine (MD -0.76 on a 0 to 10 numeric analogue scale (NAS), 95% CI -1.50 to -0.02; 1 study, 38 participants). A change of 2 points represents a MCID. No data were reported on pain and adverse events in the included study. Topical therapies versus relevant comparators There is moderate-certainty evidence that enalapril ointment probably decreases mean burn-related pruritus compared with placebo control (MD -0.70 on a 0 to 4 scoring table for itching, 95% CI -1.04 to -0.36; 1 study, 60 participants). No data were reported on pain and adverse events in the included study. Physical modalities versus relevant comparators Compared with standard care, there is low-certainty evidence that massage may reduce burn-related pruritus (standardised mean difference (SMD) -0.86, 95% CI -1.45 to -0.27; 2 studies, 166 participants) and pain (SMD -1.32, 95% CI -1.66 to -0.98). These SMDs equate to a 4.60-point reduction in pruritus and a 3.74-point reduction in pain on a 10-point VAS. A change of 2 VAS points in itch represents a MCID. No data were reported on adverse events in the included studies. There is low-certainty evidence that extracorporeal shock wave therapy (ESWT) may reduce burn-related pruritus compared with sham stimulation (SMD -1.20, 95% CI -1.65 to -0.75; 2 studies, 91 participants). This equates to a 5.93-point reduction in pruritus on a 22-point 12-item Pruritus Severity Scale. There is low-certainty evidence that ESWT may reduce pain compared with sham stimulation (MD 2.96 on a 0 to 25 pressure pain threshold (PPT), 95% CI 1.76 to 4.16; 1 study, 45 participants). No data were reported on adverse events in the included studies. Laser scar revision versus untreated or placebo controls There is moderate-certainty evidence that pulsed high-intensity laser probably results in a reduction in burn-related pruritus intensity compared with placebo laser (MD -0.51 on a 0 to 1 Itch Severity Scale (ISS), 95% CI -0.64 to -0.38; 1 study, 49 participants). There is moderate-certainty evidence that pulsed high-intensity laser probably reduces pain compared with placebo laser (MD -3.23 VAS, 95% CI -5.41 to -1.05; 1 study, 49 participants). No data were reported on adverse events in the included studies. AUTHORS' CONCLUSIONS: There is moderate to low-certainty evidence on the effects of 21 interventions. Most studies were small and at a high risk of bias related to blinding and incomplete outcome data. Where there is moderate-certainty evidence, practitioners should consider the applicability of the evidence for their patients.

Purely ionically bonded cation paving the way to ultralow thermal conductivity and large thermoelectric figure of merit in Ruddlesden-Popper perovskite Cs2SnI2Br2.

Lower dimensional materials have gained quite a bit of popularity in the last few decades. Perovskite materials have been studied extensively for their photovoltaic properties. But for large scale application of photovoltaic materials, the thermal properties need to be studied. In this work, using first principles calculations, we have studied the thermal conductivity and thermoelectric performance of quasi two-dimensional (2D) Ruddlesden-Popper phase of perovskite, Cs2SnI2Br2. The Cs atoms are found to be ionically bonded to the halogens leading to low elastic constants and hence give rise to weak bonding. The large anharmonicity in this material causes the lattice thermal conductivity to be ultralow having a value of 0.30 W·m-1·K-1at 300 K and therefore the thermoelectric figure of merit has been found to be high with a maximum value of 2.08 at 600 K. This lead-free 2D perovskite can be the precursor to a wide variety of similar materials with ultralow thermal conductivity.

Remarkable enhancement of the adsorption and diffusion performance of alkali ions in two-dimensional (2D) transition metal oxide monolayers via Ru-doping.

Transition metal oxides (TMO) are the preferred materials for metal ion battery cathodes because of their high redox potentials and good metal-ion intercalation capacity, which serve as an outstanding replacement for layered sulphide. In this work, using first-principles calculations based on Density functional theory approach, we explored the structural and electronic properties which comprise of adsorption and diffusion behaviour along with the analysis of voltage profile and storage capacity of Ru doped two-dimensional transition metal oxide [Formula: see text], [Formula: see text], and [Formula: see text] monolayers. The adsorption of alkali ions (Li, Na) to the surface of TMOs is strengthened by Ru-atom doping. Ru doping enhanced the adsorption energy of Li/Na-ion by 25%/11% for [Formula: see text], 8%/13% for [Formula: see text], and 10%/11% [Formula: see text] respectively. The open circuit voltage (OCV) also increases due to the high adsorption capacity of doped Monolayers. Ru doping makes the semiconducting TMOs conduct, which is suitable for battery application. As alkali ion moves closer to the dopant site, the adsorption energy increases. When alkali ions are close to the vicinity of doping site, their diffusion barrier decrease and rises as they go further away. Our current findings will be useful in finding ways to improve the storage performance of 2D oxide materials for application in energy harvesting and green energy architecture.

Van Hove singularity driven enhancement of superconductivity in two-dimensional tungsten monofluoride (WF).

Superconductivity in two-dimensional materials has gained significant attention in the last few years. In this work, we report phonon-mediated superconductivity investigations in monolayer Tungsten monofluoride (WF) by solving anisotropic Migdal Eliashberg equations as implemented in EPW. By employing first-principles calculations, our examination of phonon dispersion spectra suggests that WF is dynamically stable. Our results show that WF has weak electron-phonon coupling (EPC) strength (λ) of 0.49 with superconducting transition temperature (Tc) of 2.6 K. A saddle point is observed at 0.11 eV below the Fermi level (EF) of WF, which corresponds to the Van Hove singularity (VHS). On shifting the Fermi level to the VHS by hole doping (3.7 × 1014cm-2), the EPC strength increases to 0.93, which leads to an increase in theTcto 11 K. However, the superconducting transition temperature of both pristine and doped WF increases to approximately 7.2 K and 17.2 K, respectively, by applying the Full Bandwidth (FBW) anisotropic Migdal-Eliashberg equations. Our results provide a platform for the experimental realization of superconductivity in WF and enhancement of the superconducting transition temperature by adjusting the position ofEFto the VHS.

Phonon-mediated superconductivity in [Formula: see text] compounds: a crystal prediction via cluster expansion and particle-swarm optimization.

Investigating superconductivity represents one of the most significant phenomena in the field of condensed matter physics. Our simulations aim to elucidate the structures in the metallic state of Mg1-xMoxB2, which is essential for predicting their superconducting properties. By employing a first-principle cluster expansion and particle-swarm optimization, we have predicted the structures of Mg1-xMoxB2 ternary alloys, including Mg0.667Mo0.333B2, Mg0.5Mo0.5B2, and Mg0.333Mo0.667B2, and have determined their thermodynamically stable configurations under both atmospheric and high-pressure conditions. To investigate the potential for superconductivity in these structures, we have conducted a detailed examination of electronic properties that are pertinent to determining the superconducting state. Regarding superconducting properties, Mg0.333Mo0.667B2 exhibits superconductivity with a critical temperature (Tc) of 7.4 K at ambient pressure. These findings suggest that the theoretically predicted structures in Mg/Mo-substituted metal borides could play a significant role in synthesis and offer valuable insights into superconducting materials.

Anisotropic properties of two-dimensional (2D) tin dihalide (SnX2, X = Cl, Br, I) monolayer binary materials.

This paper investigated the electronic properties and photoresponse of two-dimensional SnX2(X = Cl, Br, I) monolayer binary materials using computational techniques. The calculated band structure and density of states indicate that these are large band gap semiconducting materials with an indirect band gap. The studied chemical bonding mechanism shows the existence of the hybrid bonding of ionic and covalent bonds in these dihalide materials. The valence band (VB) and conduction band (CB) edge positions are also estimated, using the concept of electronegativity and band gap, to investigate the photocatalytic activity of SnX2. Next, we investigated the polarization and energy-dependent dielectric and optical functions along the crystallographic axes of these materials in the linear response approach of the perturbing incident oscillating light field. These materials exhibit an anisotropic behavior of these functions, especially in the high-energy visible and low-energy ultraviolet (UV) regions. The absorption of incident light photons is very fast in SnI2than SnBr2and SnCl2in the low-energy UV region. It demonstrates the higher absorption coefficient and optical conductivity in Snl2. The obtained average static refractive index of SnCl2is comparable to that of glass (1.5), showing its application as transparent material. The low reflection coefficient, less than 20%, makes them superior for antireflection coating materials in the infrared and visible regions. The prominent energy loss peaks show the existence of plasmon resonances in these materials. The most of losses occur in the UV region. The investigated electronic and photoresponse properties indicate that these Sn-based dihalide materials are excellent for electronic devices and optoelectronic applications. Also, the calculated VB and CB edge positions with respect to the normal hydrogen electrode show the favorable water-splitting capability of these materials.

Viscous fingering instabilities in spontaneously formed blisters of MoS2 multilayers.

The viscous fingering in the Hele-Shaw cell can be suppressed by replacing the upper-bounding rigid plate with an elastic membrane. Recently, graphene multilayers while polymer-curing-induced blistering showed the dynamical evolution of viscous fingering patterns on a viscoelastic substrate due to their thickness-dependent elasticity. Under certain conditions, the elastic solid-based instability couples with the viscoelastic substrate-based instability. The mechanisms underlying such a coupling in the blisters of 2D materials and the dynamical evolution of the viscous fingering patterns underneath the blisters are yet to be addressed. Herein, we investigate the viscous fingering instabilities in spontaneously formed blisters of MoS2 multilayers, and provide thorough analytical and experimental insights for the elucidation of the dynamical evolution of the viscous fingering patterns and the coupled instabilities in the blisters. We also estimate the interfacial adhesion energy of the MoS2 flakes over a (poly)vinyl alcohol (PVA) substrate and the confinement pressure inside the MoS2 blisters using a conventional blister-test model. It is observed that the presence of instability gives rise to anomalies in the modeling of the blister test. The adhesion mechanical insights would be beneficial for fundamental research as well as practical applications of 2D material blisters in flexible optoelectronics.

Incorporation of Th4+ and Sr2+ into Rhabdophane/Monazite by Wet Chemistry: Structure and Phase Stability.

Rhabdophane is an important permeable reactive barrier to enrich radionuclides from groundwater and has been envisaged to host radionuclides in the backend of the nuclear fuel cycle. However, understanding of how An4+ and Sr2+ precipitate into rhabdophane by wet chemistry has not been resolved. In this work, Th4+ and Sr2+ incorporation in the rhabdophane/monazite structure as La1-2xSrxThxPO4·nH2O solid solutions is successfully achieved in the acid solution at 90 °C. Some specific issues such as lattice occupation of Th4+ and Sr2+, precipitation reaction kinetics, and crystal growth affected by starting stoichiometry are discussed in detail, along with investigating the chemical stability of La1-2xSrxThxPO4·nH2O precipitations and associated La1-2xSrxThxPO4 monazite. The results reveal that the excess of Sr2+ appears to be a prevailing factor with a suggested initial Sr: Th ≥ 2 to obtain the stability domain of La1-2xSrxThxPO4·nH2O (x = 0∼ 0.1). A rapid ion removal associated with a nucleation process has been observed within 8 h, and Th4+ can be removed more than 98% after 24 h in 0.01 mol/L solutions. From structural energetics based on density functional theory, the lattice occupation of Th4+ and Sr2+ is energetically favorable in nonhydrated lattice sites of [LaO8], although two-thirds of lattice sites are associated with [LaO8·H2O] hydrated sites. Intriguingly, the crystal transformation from rhabdophane to monazite associated with the transformation from [SrO8] to [SrO9] polyhedra can greatly improve the leaching stability of Sr2+.

On using non-Kekulé triangular graphene quantum dots for scavenging hazardous sulfur hexafluoride components.

The goal of present study is to explore how the size and functionalization of graphene quantum dots (GQDs) affect their sensing capabilities. Specifically, we investigated the adsorption of SO2, SOF2, SO2F2, and SF6 on GQDs that were functionalized with -CH3, -COCH3, and -NH2. We used density functional theory to analyse the electronic properties of these functionalized GQDs and found that the functionalization significantly altered their electronic properties. For example, the B3LYP H-L gap of pristine triangulene was 3.9eV, while the H-L gap of functionalized triangulene ranged from 2.8 eV to 3.6 eV (using the B3LYP functional). Our results indicate that -NH2 functionalized phenalenyl and triangulene provide strong interaction with SO2, with adsorption energies of -0.429 eV and -0.427 eV, respectively. These adsorption properties exhibit physisorption, leading to high gas sensitivity and superior recovery time. The findings of this study provide new insights into the potential use of GQDs for detecting the decomposed constituents of sulfur hexafluoride, which can be beneficial for assessing the operation status of SF6 insulated devices. Overall, our calculations suggest that functionalized GQDs can be employed in gas insulated systems for partial discharge detection.

Quadra-Stable Dynamics of p53 and PTEN in the DNA Damage Response.

Cell fate determination is a complex process that is frequently described as cells traveling on rugged pathways, beginning with DNA damage response (DDR). Tumor protein p53 (p53) and phosphatase and tensin homolog (PTEN) are two critical players in this process. Although both of these proteins are known to be key cell fate regulators, the exact mechanism by which they collaborate in the DDR remains unknown. Thus, we propose a dynamic Boolean network. Our model incorporates experimental data obtained from NSCLC cells and is the first of its kind. Our network's wild-type system shows that DDR activates the G2/M checkpoint, and this triggers a cascade of events, involving p53 and PTEN, that ultimately lead to the four potential phenotypes: cell cycle arrest, senescence, autophagy, and apoptosis (quadra-stable dynamics). The network predictions correspond with the gain-and-loss of function investigations in the additional two cell lines (HeLa and MCF-7). Our findings imply that p53 and PTEN act as molecular switches that activate or deactivate specific pathways to govern cell fate decisions. Thus, our network facilitates the direct investigation of quadruplicate cell fate decisions in DDR. Therefore, we concluded that concurrently controlling PTEN and p53 dynamics may be a viable strategy for enhancing clinical outcomes.

Unveiling the local structure of the amorphous metal [Formula: see text] combining first-principles-based simulations and modelling of EXAFS spectra.

Amorphous alloys exhibit useful properties such as the excellent soft magnetic behaviour of Fe-based metallic glasses. The detailed structure of amorphous [Formula: see text] with x = 0.07, 0.10, and 0.20 is in this work explored through a synergetic combination of atomistic simulations and experimental characterisation. Thin-film samples were investigated using X-ray diffraction and extended X-ray absorption fine structure (EXAFS), while the corresponding atomic structures were simulated using an efficient first-principles-based method called stochastic quenching (SQ). The simulated local atomic arrangements are investigated by constructing the radial- and angular-distribution functions, as well as by Voronoi tesselation. The radial distribution functions are then used to construct a model to fit simultaneously the experimental EXAFS data of multiple samples with different compositions, creating a simple yet accurate description of the atomic structures valid for any composition in the range x = 0.07 to 0.20, using a minimal number of free parameters. This approach significantly improves the accuracy of the fitted parameters and allows us to relate the compositional dependence of the amorphous structures with the magnetic properties. The proposed EXAFS fitting process can be generalised to other amorphous systems, contributing to the understanding of structure-property relationships and the development of amorphous alloys with tailored functional properties.

Hoop compression driven instabilities in spontaneously formed multilayer graphene blisters over a polymeric substrate.

The blistering of elastic membranes is prone to elastic-solid as well as substrate-based mechanical instabilities. The solid-based instabilities have been well-explored in the mechanically indented blisters of elastic membranes over the rigid/solid substrates, but an integrated study illustrating the underlying mechanism for the onset of solid as well as substrate-based instabilities in the spontaneous blistering of a 2D material is still lacking in the literature. In this article, an extensive experimental as well as analytical analysis of the spontaneous blister-formation in the multilayer graphene (MLG) flakes over a polymeric substrate is reported, which elucidates the involved mechanism and the governing parameters behind the development of elastic-solid as well as viscoelastic-substrate based instabilities. Herein, a 'blister-collapse model' is proposed, which infers that the suppression of the hoop compression, resulting from the phase-transition of the confined matter, plays a crucial role in the development of the instabilities. The ratio of blister-height to flake-thickness is a direct consequence of the taper-angle of the MLG blister and the thickness-dependent elasticity of the upper-bounding MLG flake, which shows a significant impact on the growth-dynamics of the viscous fingering pattern (viscoelastic-substrate based instability) under the MLG blister.

Lattice dynamic stability and electronic structures of ternary hydrides La1-x Y x H3 via first-principles cluster expansion.

Lanthanum hydride compounds LaH3 become stabilized by yttrium substitution under the influence of moderate pressure. Novel materials with a wide range of changes in the structural properties as a function of hydrogen are investigated by means of the first-principles cluster expansion technique. Herein, the new compounds La1-x Y x H3, where 0 ≤ x ≤ 1, are determined to adopt tetragonal structures under high-pressure with the compositions La0.8Y0.2H3, La0.75Y0.25H3, and La0.5Y0.5H3. The corresponding thermodynamic and dynamical stabilities of the predicted phases are confirmed by a series of calculations including, for example, phonon dispersion, electronic band structure, and other electronic characteristics. According to the band characteristics, all hydrides except that of I41/amd symmetry are semiconductors. The tetragonal La0.5Y0.5H3 phase is found to become semi-metallic, as confirmed by adopting the modified Becke-Johnson exchange potential. The physical origins of the semiconductor properties in these stable hydrides are discussed in detail. Our findings provide a deeper insight into this class of rare-earth ternary hydrides.

Putative targeting by BX795 causes decrease in protein kinase C protein levels and inhibition of HSV1 infection.

Herpes simplex virus type-1 (HSV1) exploits cellular machinery for its own replicative advantage. Current treatment modalities against HSV1 cause toxicity and drug resistance issues. In the search for alternative forms of treatment, we have uncovered a small molecule, BX795, as a candidate drug with strong antiviral potential owing to its multitargeted mode of action. In this study, we show that in addition to a previously known mechanism of action, BX795 can directly interact with the proviral host factor protein kinase C (PKC) in silico. When administered to HSV1 or mock infected human corneal epithelial (HCE) cells, BX795 significantly reduces the protein level and perinuclear localization of proviral PKC-α and PKC-ζ isoforms. This activity closely mimics that of a known PKC inhibitor, Bisindolylmaleimide I (BIM I), which also inhibits viral replication. Taken together our studies demonstrate a previously unknown mechanism by which BX795 exerts its antiviral potential.

Network analysis reveals that the tumor suppressor lncRNA GAS5 acts as a double-edged sword in response to DNA damage in gastric cancer.

The lncRNA GAS5 acts as a tumor suppressor and is downregulated in gastric cancer (GC). In contrast, E2F1, an important transcription factor and tumor promoter, directly inhibits miR-34c expression in GC cell lines. Furthermore, in the corresponding GC cell lines, lncRNA GAS5 directly targets E2F1. However, lncRNA GAS5 and miR-34c remain to be studied in conjunction with GC. Here, we present a dynamic Boolean network to classify gene regulation between these two non-coding RNAs (ncRNAs) in GC. This is the first study to show that lncRNA GAS5 can positively regulate miR-34c in GC through a previously unknown molecular pathway coupling lncRNA/miRNA. We compared our network to several in-vivo/in-vitro experiments and obtained an excellent agreement. We revealed that lncRNA GAS5 regulates miR-34c by targeting E2F1. Additionally, we found that lncRNA GAS5, independently of p53, inhibits GC proliferation through the ATM/p38 MAPK signaling pathway. Accordingly, our results support that E2F1 is an engaging target of drug development in tumor growth and aggressive proliferation of GC, and favorable results can be achieved through tumor suppressor lncRNA GAS5/miR-34c axis in GC. Thus, our findings unlock a new avenue for GC treatment in response to DNA damage by these ncRNAs.

2D Dumbbell Silicene as a High Storage Capacity and Fast Ion Diffusion Anode for Li-Ion Batteries.

First-principles calculations within DFT have been performed to investigate the use of a recently synthesized form of silicene, the dumbbell (DB) silicene as an anode material for Li-ion batteries (LiBs). The energetically most stable geometries for Li adsorption on DB silicene were investigated, and the energy barriers for Li-ion diffusion among the possible stable adsorption sites were calculated. We found that DB silicene can be lithiated up to a ratio of 1.05 Li per Si atom, resulting in a high storage capacity of 1002 mA h g-1 and an average open-circuit potential of 0.38 V, which makes DB silicene suitable for applications as an anode in LiBs. The energy barrier for Li-ion diffusion was calculated to be as low as 0.19 eV, suggesting that the Li ions can easily diffuse on the entire DB silicene surface, decreasing the time for the charge/discharge process of the LiBs. Our detailed investigations show that the most stable form of two-dimensional silicon has characteristic features suitable for application in high-performance LiBs.

Pyrophosphate Na2CoP2O7 Polymorphs as Efficient Bifunctional Oxygen Electrocatalysts for Zinc-Air Batteries.

Developing earth-abundant low-cost bifunctional oxygen electrocatalysts is a key approach to realizing efficient energy storage and conversion. By exploring Co-based sodium battery materials, here we have unveiled nanostructured pyrophosphate Na2CoP2O7 polymorphs displaying efficient bifunctional electrocatalytic activity. While the orthorhombic polymorph (o-NCPy) has superior oxygen evolution reaction (OER) activity, the triclinic polymorph (t-NCPy) delivers better oxygen reduction reaction (ORR) activity. Simply by tuning the annealing condition, these pyrophosphate polymorphs can be easily prepared at temperatures as low as 500 °C. The electrocatalytic activity is rooted in the Co redox center with the (100) active surface and stable structural framework as per ab initio calculations. It marks the first case of phospho-anionic systems with both polymorphs showing stable bifunctional activity with low combined overpotential (ca. ∼0.7 V) comparable to that of reported state-of-the-art catalysts. These nanoscale cobalt pyrophosphates can be implemented in rechargeable zinc-air batteries.

Contact electrification through interfacial charge transfer: a mechanistic viewpoint on solid-liquid interfaces.

Contact electrification (triboelectrification) has been a long-standing phenomenon for 2600 years. The scientific understanding of contact electrification (triboelectrification) remains un-unified as the term itself implies complex phenomena involving mechanical contact/sliding of two materials involving many physico-chemical processes. Recent experimental evidence suggests that electron transfer occurs in contact electrification between solids and liquids besides the traditional belief of ion adsorption. Here, we have illustrated the Density Functional Theory (DFT) formalism based on a first-principles theory coupled with temperature-dependent ab initio molecular dynamics to describe the phenomenon of interfacial charge transfer. The model captures charge transfer dynamics upon adsorption of different ions and molecules on AlN (001), GaN (001), and Si (001) surfaces, which reveals the influence of interfacial charge transfer and can predict charge transfer differences between materials. We have depicted the substantial difference in charge transfer between fluids and solids when different ions (ions that contribute to physiological pH variations in aqueous solutions, e.g., HCl for acidic pH, and NaOH for alkaline pH) are adsorbed on the surfaces. Moreover, a clear picture has been provided based on the electron localization function as conclusive evidence of contact electrification, which may shed light on solid-liquid interfaces.

Superconducting Gap of Pressure Stabilized (Al0.5Zr0.5)H3 from Ab Initio Anisotropic Migdal-Eliashberg Theory.

Motivated by Matthias' sixth rule for finding new superconducting materials in a cubic symmetry, we report the cluster expansion calculations, based on the density functional theory, of the superconducting properties of Al0.5Zr0.5H3. The Al0.5Zr0.5H3 structure is thermodynamically and dynamically stable up to at least 200 GPa. The structural properties suggest that the Al0.5Zr0.5H3 structure is a metallic. We calculate a superconducting transition temperature using the Allen-Dynes modified McMillan equation and anisotropic Migdal-Eliashberg equation. As result of this, the anisotropic Migdal-Eliashberg equation demonstrated that it exhibits superconductivity under high pressure with relatively high-T c of 55.3 K at a pressure of 100 GPa among a family of simple cubic structures. Therefore, these findings suggest that superconductivity could be observed experimentally in Al0.5Zr0.5H3.