Alkali Metals - Science topic

The resonant charge transfer process based on the jellium model of free electron gas is normally used to explain the neutralization of alkali-metal ions scattering on metal surfaces with low work functions. However, we find it cannot adequately account for the angle dependent neutralization of keV-energy Na+ ions in grazing scattering on Al(100) an...

Electromagnetically induced transparency (EIT) is an important quantum optical phenomenon which provides a crucial tool for light manipulation. However, typically the transparency window is broad, limited by the coherence time of the metastable state. Here, we show that an extremely narrow transparency window can be realized using nuclear spin indu...

A series of dicobalt(III) metallohosts, [LCo2A4](OTf)2, which have different auxiliary amine ligands A (=EtNH2, PhCH2NH2, PhC2H4NH2, PhC3H6NH2), were synthesized in order to investigate the tuning of the guest uptake/release kinetics without significantly affecting the guest binding affinity. The metallohosts were characterized by spectroscopic met...

Tandem organic light‐emitting diodes (OLEDs), where more than one electroluminescence (EL) units are connected electrically in series by charge generation layers (CGLs), have aroused wide attention for high‐luminance tandem displays. However, the n‐doped layer in commercialized CGL still relies on the active low‐work function alkali metals and suff...

This study presents a novel comparative method for determining the thermal conductivity coefficient of granular silicon doped with alkali metal atoms. The experimental setup utilizes a three-layer disk configuration, where the same heat flow is passed through two distinct material samples. Temperature measurements are taken separately between each...

This study uses the density functional theory (DFT) approach with GGA-PBE to assess the effect of substituting alkali metals in Rb$_{2}$CaH and Cs-doped Rb$_{2}$CaH$_{4}$ on their hydrogen storage potential. To address the challenges associated with predicting accurate electronic properties in materials containing heavier elements such as cesium, s...

Fe single atom catalysts (SACs) with high coordination numbers have emerged as high-performance catalysts for the conversion of CO2 to CO. However, the influence of alkali cations at the catalyst–electrolyte interface has not yet been understood clearly. Here, we investigate the role of various alkali metal cations (Na⁺, K⁺, Rb⁺) in catalytic CO2 r...

The efficient neutralization of alkali-metal ions on high-work-function metal surfaces at low incident energies has not been understood well at present. To study this mechanism, we measured the neutral fraction of Na+ ions scattering on the high-work-function Pd(111) and Au(111) surfaces at the 7o scattering angle in the energy range of 0.2-5 keV....

Supplementary cementitious materials (SCMs) can mitigate alkali-silica reaction by lowering the alkali metal concentration in the pore solution. This is a theoretical study on the applicability of a thermodynamic model (GEMS) and the empirical Taylor model to predict the required replacement level of portland cement (PC) by SCMs to achieve an alkal...

During the extraction and utilization of coal resources, a large amount of CO2 and coal-based solid wastes (CBSW), such as coal gangue, are generated. To reduce the carbon and waste emissions, an effective approach is to mineralize the CO2 with the CBSW and then backfill the mineralized materials into the goaf area. However, efficient CO2 mineraliz...

Solid‐state alkali‐metal batteries experience dendrite growth require a robust solid‐electrolyte interphase (SEI) and high deformation resistance of electrolytes to stabilize the electrolyte/metal interface. However, the traditional dual‐ion polymer electrolyte with large thickness has a low ion transference number and insufficient mechanical stabi...

The development of catalysts for the direct one‐step conversion of syngas to higher alcohols is still a challenge. In this study, different alkali metal‐modified MCoMo/Al2O3 (M = Li, Na, K, and Cs) catalysts were prepared by impregnation and temperature‐programmed carbonization process. Characterization by XRD, H2‐TPR, and XPS revealed that the int...

Various of factors have contributed to groundwater contamination in the Indo-Gangetic alluvium, including mineral deposits, ion exchange, precipitation, overexploitation, and dissolution. In the current study, 40 different groundwater samples were sampled from different locations of Sadar block Pratapgarh district, Uttar Pradesh and various physico...

Long wave infrared (LWIR) birefringent crystals are essential for infrared optical applications but such materials are rarely reported due to the requirements of large birefringence and wide infrared transmission range. This study proposes a facile route to create new LWIR birefringent crystal by oxygenation strategy in halides with cations contain...

This paper presents the results of the study of vanadium extraction process in alunite processing, as well as modeling and finding the optimal reaction conditions. Vanadium is widely used mainly in ferrous and non-ferrous metallurgical alloys. Alloys of vanadium with iron, titanium, nickel, aluminum, chromium and other metals are used as catalysts...

Electromagnetically induced transparency (EIT) is an important quantum optical phenomenon which provides a crucial tool for light manipulation. However, typically the transparency window is broad, limited by the coherence time of the metastable state. Here we show that extremely narrow transparency window can be realized using nuclear spin induced...

The ubiquitous, evolutionarily oldest RNAs and proteins exclusively use rather rare zinc as transition metal cofactor and potassium as alkali metal cofactor, which implies their abundance in the habitats of the first organisms. Intriguingly, lunar rocks contain a hundred times less zinc and ten times less potassium than the Earth’s crust; the Moon...

We theoretically investigate the spin structure of weakly bound diatomic van der Waals molecules formed by two identical bosonic alkali atoms. Our studies were performed using known Born-Oppenheimer potentials while developing a reduced interaction potential model. Such reduced potential models are currently a key for solving certain classes of few...

Bias instability is one of the most critical factors in the performance of spin-exchange relaxation-free (SERF) co-magnetometers. Previous studies on SERF co-magnetometers have shown that changes in the atomic ensemble temperature can lead to variations in the alkali metal atom density, which in turn affect the optical rotation angle and light shif...

This work presents an economic analysis of processing various titanium-containing raw materials-titanium slag and synthetic rutile-through chlorination in a molten salt medium in the presence of carbon. The processing of titanium-containing raw materials is carried out using a chlorination technology in molten alkali metal salts (MgCl₂, NaCl, KCl)...

Laser spectroscopy of hot atomic vapours has been studied extensively. Theoretical models that predict the absolute value of the electric susceptibility are crucial for optimising the design of photonic devices that use hot vapours, and for extracting parameters, such as external fields, when these devices are used as sensors. To date, most of the...

The O3-type layered oxide represents a highly promising candidate for sodium-ion batteries (SIBs). However, the intrinsic stability law of these cathodes remains elusive due to the complex phase transition mechanism and migration of transition metal (TM) ions. Here, we underscore how the ratio between the spacings of alkali metal layer and TM layer...

The object of the study is the catalytic activity of potassium glyceroxide in the chemical transesterification reaction of palm olein. Transesterification is an important method for obtaining fats with desired properties, surfactants, alternative biofuels, etc. Industrial catalysts for chemical transesterification are explosive, flammable, and quic...

Despite the high theoretical capacity, the deposition of solid alkali metals can trigger dendrites growth, causing safety risk, capacity and life decay. While liquid NaK alloy is dendrite‐free, their fluidity may cause leakage or even short circuit. In this work, a novel controllable phase transformation strategy was proposed enabled NaK anode to b...

Cesium (Cs) and rubidium (Rb) are important rare alkali metal elements that are scarce and dispersed in nature. They often coexist with high amounts of Na⁺ and K⁺. In this study, copper hexacyanoferrate (CuHCF) was used as a co‐precipitant to enrich Cs⁺ and Rb⁺ in a high‐salt solution. The effect of parameters, such as type and dose of divalent met...

This study focuses on the comprehensive characterization of five major paddy straw varieties in Punjab—PB 370, PB 1121, PR 121, PR 126, and Pusa 44. Among the varieties, PB 370 exhibited the highest heating value (HHV) at 15.15 MJ/kg, while PR 121 had the lowest ash content at 12.04%. Statistical analysis revealed that PR 126 exhibited statisticall...

Plasmonics offers a groundbreaking avenue for manipulating light beyond the diffraction limit, finding utility in diverse applications ranging from optical cloaking and chemical sensing to super-resolution imaging. Despite these promising applications, plasmonic devices are always born with significant energy dissipation, posing substantial challen...

Finding stable binding sites of alkali metal ions on two-dimensional transition metal dichalcogenides (TMDs) is crucial for predicting and engineering the usage of these materials in batteries and optoelectronic devices. However, conventional approaches using density functional theory (DFT), where the energies of the intercalated layers are analyze...

Glucose transformation to methyl lactate was investigated over microporous Sn-H-Y- zeolite with SiO2/Al2O3 ratio of 30 as well as alkali metal modified mesoporous dealuminated Sn-H-Y-zeolites in the temperature range of 150-180oC. The catalysts were synthesized either by evaporation-impregnation or ion-exchange methods using a two-step procedure fo...

The present investigation delved into the geochemical importance of trace elements and major oxide constituents in the shales from the Gamba Formation, Sokoto Basin, Nigeria. by inductively coupled plasma-mass spectrometry (ICP-MS), x-ray fluorescence spectroscopy (XRF), and statistical methodologies within the context of provenance, tectonic envir...

Fe─Mo catalysts are widely employed in the commercial oxidation of methanol to formaldehyde. This study investigates the influence of alkali metal promoters (Li, Na, and K) on the morphology, structure, surface properties, and catalytic performance of Fe─Mo catalysts. A comprehensive array of characterization techniques, including SEM‐EDS, XRD, FTI...

Unveiling the so far ambiguous mechanism of the significant dependence on the identity of alkali metal cation would prompt opportunities to solve the more than two orders of magnitude slowdown of hydrogen electrocatalytic kinetics in base relative to acid, which has hampered the effort to reduce the precious metal usage in fuel cells by using the h...

With the pressure for renewable energy resources and the enchantingly digitalized current lifestyle, the need for batteries will augment. Therefore, in this article, it has been evaluated the promising alternative alkali metals of sodium-ion and potassium-ion, batteries. The hypothesis of the hydrogen adsorption phenomenon was confirmed by density...

Layered transition metal oxides for sodium-ion batteries are regarded as the most promising cathode materials for commercialization owing to their high theoretical specific capacity, high rate performance, and low cost. However, their drawbacks, such as unfavorable phase transitions, Na⁺/vacancy disorder, and slow dynamics, seriously hinder their f...

In the quest for novel thermoelectric materials to harvest waste environmental heat, we investigate alkali metal-based Zintl phases X$_2$AgY (X = Na, K, and Y = Sb, Bi) utilizing first-principles methods. We obtain significantly low lattice thermal conductivity values ranging 0.9-0.5 W m$^{-1}$ K$^{-1}$ at 300~K, challenging established thermoelect...

Heading errors of atomic magnetometers refer to the dependence of measurement results on the sensor orientation with respect to the external magnetic field. There are three main sources of such errors: the light shift effect, the linear nuclear-spin Zeeman effect, and the nonlinear Zeeman effect. In this work, we suppress the former two effects by...

Alkaline earth sulfides are possibly abundant in the mantle of Mercury, and knowledge of their melting and transport properties is needed to investigate the structure of the planet. We report electrical experiments at pressures in the range 2–5 GPa and at temperatures up to ∼2,400 K on proposed analogs of natural sulfides, that is, Ca1‐xMgxS with m...

To enhance the effective cohesion between basalt fiber (BF) and asphalt, an optimal preparation process of nano‐SiO2 bioinspired grafting BF was proposed using a chemical grafting method based on the bioinspired idea of mussel‐plaque. The mechanism of nano‐SiO2 bioinspired grafted BF was analyzed through micro‐morphology, functional group changes,...

The electrode-electrolyte interfaces play pivotal roles in alkali-metal batteries, necessitating superior electrochemical stability, excellent electrical insulation, and high ionic conductivity. This study proposes using zeolites as interfacial protective layers owing to their inherently high stability with both alkali metals and high-voltage catho...

Catalytic enantioconvergent nucleophilic substitution reactions of alkyl halides are highly valuable transformations, but they are notoriously difficult to implement. Specifically, nucleophilic fluorination is a renowned challenge, especially when inexpensive alkali metal fluorides are used as fluorinating reagents due to their low solubility, high...

As a potential substitute for traditional nonaqueous organic electrolytes, polymer‐based solid‐state electrolytes (SSEs) have the advantages of high safety, flexibility, low density, and easy processing. In contrast, they still face challenges, such as low room‐temperature ionic conductivity, narrow electrochemical windows, and poor mechanical stre...

This study presents evidence that the discharge products of positive electrodes in metal–oxygen batteries using Rb- and Cs-based electrolytes are RbO2 and CsO2, paralleling the findings for Na- and K-based systems. We explored the positive electrode reaction inside alkali metal–oxygen batteries, revealing that the stability of MO2 compounds (M = Na...

Review Demystifying the Potential of Anode-Less Alkali Metal Batteries: Uncovering the Role of Liquid and Solid Electrolyte Combinations Shruti Kannan and Ananthakumar Ramadoss * Advanced Research School for Technology & Product Simulation (ARSTPS), School for Advanced Research in Petrochemicals (SARP), Central Institute of Petrochemicals Engineeri...

The combustion characteristics and gas emissions behavior of Low-calorie Indonesian coal (LC), Shaanxi coal (SC), and Datong coal (TC) were analyzed by a thermogravimetric-Fourier transform infrared spectrometer (TG-FTIR). The results showed that LC was the easiest coal to burn, followed by SC and TC. The main components of LC ash were alkali metal...

The polyether ionophore monensin A (MonH), applied as silver monensinate, reacts with caesium cations to form a dinuclear complex [Mon2Cs2] the structure of which has been solved by single‐crystal X‐ray diffraction. Two Cs⁺ ions are located in the hydrophilic cage of two ligand anions, achieving coordination number eight. In addition, the metal cat...

The measurement of Rydberg atoms in low-frequency electric fields is hindered due to the shielding effect of the vapor cell against low-frequency electric fields. This study analyzes the electric field shielding effect of Vapor Cell in Rydberg atom electric field sensors, which arises primarily from the polarization charges generated in dielectric...

As an emerging photovoltaic material, antimony selenosulfide (Sb2(S,Se)3) has attracted considerable attention and research enthusiasm. However, the current solution‐processed Sb2(S,Se)3 layers suffer from severe unfavorable energy band structure problems attributed to the vertical gradient‐variable Se/S atomic ratio, making it a challenging and pr...

Semiconductor crystals driven by strong mid-infrared pulses offer advantages for studying many-body physics and ultrafast optoelectronics via high-harmonic generation. While the process has been used to study solids in the presence strong mid-infrared fields, its potential as an attosecond light source is largely underexplored. We demonstrate that...

With the growing interest in reducing CO2 emissions to combat climate change, humanity is turning to green or renewable sources of electricity. There are numerous issues associated with the development of these sources. One of the key aspects of renewable energy sources is their problematic controllability, namely the control of energy production o...

This paper discusses ways to search for lead-free functional materials for various applications. Using the example of the solid solution systems based on alkali metal niobates, the influence of the position on the phase diagram of the corresponding systems, the number of the components in them, and modification with mono- and combined metal oxides...

The Franck-Condon principle and Condon approximation are key to understanding optical transitions. This study uses first-principles calculations to simulate luminescence and absorption line-shapes of hexavalent Mn ions in alkali-metal sulfates, revealing a significant Herzberg-Teller effect in this electric-dipole allowed transition. These findings...

Magneto‐optical (MO) glass, which has been garnering increasing interest for its light rotation capability, often faces challenges related to valence variations, resulting in suboptimal MO performance. The composition of the glass matrix and the specifics of the melting process are crucial in determining the glass network structure and cation valen...

Combining experiment and theory, the mechanisms of H2 activation by the potassium‐bridged aluminyl dimer K2[Al(NON)]2 (NON=4,5‐bis(2,6‐diisopropylanilido)‐2,7‐di‐tertbutyl‐9,9‐dimethylxanthene) and its monomeric K⁺‐sequestered counterpart have been investigated. These systems show diverging reactivity towards the activation of dihydrogen, with the...

Degradation of halide perovskites under a humid atmosphere is the major challenge preventing widespread commercial deployment of this material class. Here it is shown that strain engineering via alkali metal chloride treatment at the FAPbI3/SnO2 interface effectively improves moisture-related stability. CsCl and KCl treatments reduce microstrain at...

Large-scale synthesis of high-quality two-dimensional (2D) semiconductors, such as molybdenum disulfide (MoS2), is a prerequisite for their lab-to-fab transition. It is crucial to systematically explore and understand the influence of key synthetic conditions on the nucleation, uniformity, and quality of MoS2 wafers. Here, we report the epitaxial g...

Protonic ceramic fuel cells (PCFCs) are one of the promising routes to generate power efficiently from various fuels at economically viable temperatures (500–700 °C) due to the use of fast proton conducting oxides as electrolytes. However, the power density and durability of the PCFCs are still limited by their cathodes made from solid metal oxides...

Background The periodic table contains the s-block elements in groups 1 and 2. In the periodic table, they reside in the first two columns. S-block consists of 14 elements that include hydrogen (H), lithium (Li), helium (He), sodium (Na), beryllium (Be), potassium (K), magnesium (Mg), rubidium (Rb), calcium (Ca), cesium (Cs), strontium (Sr), franci...

We present experimental probes of contact ion-pair (CIP) SN2 reactions for simplest prototype systems by ¹⁹F-NMR spectroscopy. This study provides crucial evidences for the reactions of CIP metal salts facilitated by Lewis base phase transfer catalysts (PTCs) [2,2,2]-cryptand, 18-crown-6, pentaethylene glycols (pentaEGs) and BINOL–based pentaEG. Th...

Isotope Exchange processes are becoming the preferred way to prepare isotopically labelled molecules, avoiding the redesign of multistep synthetic protocols. In the case of deuterium incorporation, the most used strategy has employed transition metals, that offer high reactivity under mild reaction conditions. Despite their success, the trade‐off i...

In areas where surface water resources are scarce ground water is used to meet industrial demand. Of great concern is the large volume of water withdrawn and the much smaller volume actually consumed thus rendering a greater portion of it as waste water or effluent to be disposed off. It is the volume of these effluents and the concentration of haz...

Three alkali metal salt forms of the diuretic chlorothiazide (systematic name: 6-chloro-1,1-dioxo-2 H -1,2,4-benzothiazine-7-sulfonamide, HCTZ) are described. When crystallized from aqueous solution, the Na and K salts, namely, poly[[μ-aqua-aqua(μ 3 -6-chloro-1,1-dioxo-7-sulfamoyl-2 H -1,2,4-benzothiadiazin-2-ido)sodium] hemihydrate], {[Na(C 7 H 5...

It is known that the presence of redox-inactive metals in the active center of an enzyme has a significant effect on its activity. In this regard and for other reasons, the effect of redox-inactive metals on redox processes, such as electron transfer, oxygen and hydrogen atom transfer, as well as the breaking and formation of O–O bonds in reactions...

The present study reports the structural, electronic, magnetic, and optical properties of vanadium-doped Li2Te using the ab-initio simulations within the framework of density functional theory. To account for exchange-correlation effects, the PBE-GGA, PBE-GGA-mBJ, and PBE-GGA+U approximations were employed. Our findings reveal that the ground state...

Atomically flat two-dimensional networks of boron are attracting attention as post-graphene materials. An introduction of cations between the boron atomic layers can exhibit unique electronic functions that are not achieved by neutral graphene or its derivatives. In the present study, we propose a synthesis strategy for ion-laminated boron layered...

In this computational study, we investigate two-sided functionalised MoS2 with alkali metal atoms as donors and the organic acceptor molecule F4TCNQ as an acceptor. Characterisation of functionalised MoS2 involves first-principles calculations within the density functional theory (DFT) framework with a PBE+D3 scheme to investigate the electronic st...

We have studied the electrochemical performance of the delta-5 boron monolayer as an anode material for alkali metal (AM) and alkali earth metal (AEM) ion batteries using density functional theory simulations. The electronic properties, adsorption, diffusion rate, and storage behavior of various metal atoms (M) in the {\delta}-5 boron monolayer are...

There are likely numerous known and yet‐to‐be‐discovered alkaline earth (AE)‐alkali metal (A) thiosilicates, thioaluminates, and thiophosphates that can serve as suitable hosts for the Eu²⁺ 5d‐4f emission. These structures offer an infinite number of possible compositions, with the potential for multi‐elemental occupancy at the AE and A sites. Scre...

Rydberg states of alkali-metal atoms are highly sensitive to electromagnetic radiation in the GHz-to-THz regime because their transitions have large electric dipole moments. Consequently, environmental blackbody radiation (BBR) can couple Rydberg states together at µ s timescales. Here, we track the BBR-induced transfer of a prepared Rydberg state...

In Rydberg quantum electric field sensing, the amplitude and linewidth of electromagnetically induced transparency (EIT) spectra significantly impact the accuracy of electric field measurements. This paper discusses the influence of atomic density on the amplitude and linewidth of EIT spectra in a vapor cell within a three-level ladder system drive...

Cumulenes are molecules characterized by a series of consecutive double bonds. They serve as important reagents and intermediates in the synthesis of polymers and a wide variety of functionalized compounds, including various heterocycles. Understanding the properties of cumulenes and developing synthetic routes to these often highly reactive specie...

We employed the ONIOM model to investigate the role of alkali metals in the conversion of CO₂ and CH₄ into CH₃COOH on CuX-ZSM-5 (X = alkali metal). This hybrid model achieves high efficiency by dividing the computational system into layered regions, where key regions undergo high-accuracy quantum mechanical (QM) calculations, while the remaining re...

The integration of metal‐organic frameworks (MOFs) with functional materials has established a versatile platform for a wide range of energy storage applications. Due to their large specific surface area, high porosity, and tunable structural properties, MOFs hold significant promise as components in energy storage systems, including electrodes, el...

Alkali metal doping is a new and promising approach to enhance the photo/electrocatalytic activity of NiS-based catalyst systems. This work investigates the impact of sodium on the structural, electronic, and...

With the extremely high theoretical energy densities, secondary batteries including lithium-sulfur (Li-S) and sodium-sulfur (Na-S) batteries are anticipated to become the leading candidates among metal-sulfur batteries. However, the practical energy density and storage efficiency of Li/Na-sulfur batteries are significantly hindered by several issue...

Alkali metal intercalation of graphene layers has been of particular interest due to potential applications in electronics, energy storage, and catalysis. Rubidium (Rb) is one of the largest alkali metals and the one less investigated as intercalant. Here, we report a systematic investigation, with a multi-technique approach, of the phase formation...

Self‐assembly of α‐D nucleosides to supramolecular hydrogels is described in detail. Hydrogel formation is studied on α‐D 2’‐deoxyguanosine (α‐dG), and the fluorescent 8‐azapurine α‐D nucleosides 2‐amino‐8‐aza‐2’‐deoxyadenosine (α‐2‐NH2‐z⁸Ad) and 8‐aza‐2’‐deoxyisoguanosine (α‐z⁸iGd). These compounds were prepared from α‐D 8‐aza‐2’‐deoxyguanosine by...