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The cathodic catalytic activity for the oxygen reduction reaction (ORR) plays a critical role in determining the performance of proton-conducting solid oxide fuel cells (P-SOFCs). BaCo 0.4 Fe 0.4 Zr 0.2 O 3-δ (BCFZ) has emerged as a promising cathode for P-SOFCs due to its triple-phase conductivity. Nevertheless, its suboptimal proton conductivity and hydration ability at intermediate temperatures prevent it from achieving the anticipated ORR catalytic activity. To address these limitations, this study explores the enhancement of electrocatalytic activity in BCFZ through alkali metal doping and A-site defect construction. The effects of such modifications on oxygen surface exchange kinetics and ORR catalytic activity are systematically investigated. The findings reveal that BCFZ exhibits relatively low parameters in terms of electronic conductivity, oxygen ion conductivity, oxygen vacancy concentration, k chem , and D chem. Conversely, these parameters are markedly improved in A-site deficient BCFZ (D-BCFZ) and Na/K-doped BCFZ. Consequently, the enhancement of these properties yields a significant increase in ORR catalytic activity, with D-BCFZ demonstrating the best electrochemical performance. Specifically, P-SOFC with D-BCFZ cathode achieves an R p value of just 0.073 Ω cm2 and a P max value of 0.928 W cm−2 at 650 °C. This study provides theoretical insight into the mechanisms by how alkali metal doping and defect construction enhance the ORR catalytic activity of BCFZ. These findings offer valuable guidance for the development and optimization of high-performance P-SOFC cathodes. [ABSTRACT FROM AUTHOR]

Low stability deriving from the accumulation of moisture and intermediates represents the major challenge for practical applications of manganese oxides (MnO x) for ozone elimination. Here, Li+, Na+ and K+ were successfully introduced into the channel framework of amorphous MnO x to improve its stability through a simple post-treatment method. Alkali metal modification can promote the removal of ozone by amorphous MnO x , and Na-MnO x exhibited superior catalytic activity and remarkable stability in water-resistance, cycling and long-term tests. The Na introduction facilitated the formation of oxygen vacancies, and improved low-temperature reducibility and lattice oxygen mobility. The mechanism of ozone decomposition on amorphous MnO x and Na-MnO x catalysts was deeply investigated by in situ diffuse reflectance infrared Fourier transform spectra (in-situ DRIFTS). The Na addition strengthened the hydrophobicity of oxygen vacancies, but also greatly boosted the desorption of intermediate oxygen species and the ozone decomposition cycle. [Display omitted] [ABSTRACT FROM AUTHOR]

Alkali metal catalysts show great application potential in the gasification process of coal attributed to their characteristics of high activity and reusability. However, this type of catalysts has strong water absorption, which causes the agglomerating during storage and limits pipeline transportation by water. In order to solve the hydration of alkali metal catalysts and to release them at the target temperatures, they were encapsulated by cost effective and environment friend inorganic materials. The capsules were fabricated through in situ formation of calcium carbonate as shell. The water resistance, water erosion resistance and shell rupture temperature of the capsules were tested. And the effect of temperature on the properties of capsules was studied. The microstructure and composition were characterized by SEM and XRD. The results showed that the best performance of the capsules was obtained after heat treatment at 600 °C, with the pH of catalyst solution was reduced from 13.65 to 10.89 before and after encapsulation. The percentage of capsule breakage after 2 h of water scouring was 8.46 %. And the catalysts were fully released between 700–750 °C due to the crack of shell. The shell was composed mainly of CaCO 3 -AlPO 4 -Al 4 (P 2 O 7) 3. The shell was porous in the middle, gradually denser outwards, and eventually formed a dense layer in the outer layer. This was attributed to the volume expansion caused by the reaction of calcium oxide and calcium hydroxide to form calcium carbonate. This study provides a novel approach for the transportation of alkali metal catalyst and expands its application in coal gasification. [Display omitted] • The alkali metal catalysts were successfully encapsulated by CaCO 3 shells. • The pH of catalyst was reduced from 13.65 to 10.89 before and after encapsulation. • The percentage of capsule breakage after 2 h of water scouring was 8.46 %. • The catalysts were fully released between 700–750 °C due to the crack of shell. [ABSTRACT FROM AUTHOR]

High-yielding synthetic routes to five new extremely bulky aminopyridine pro-ligands were developed, viz. (C5H3N-6-Ar1)N(H)Ar2-2; Ar1 = Trip, Ar2 = TCHP (HAmPy1), Ar* (HAmPy2) or Ar† (HAmPy3); Ar1 = TCHP, Ar2 = Ar* (HAmPy4) or Ar† (HAmPy5) (Trip = 2,4,6-triisopropylphenyl, TCHP = 2,4,6-tricyclohexylphenyl, Ar* = C6H2(CHPh2)2Me-2,6,4, Ar† = C6H2(CHPh2)2Pri-2,6,4. Four of these were deprotonated with LiBun in diethyl ether to give lithium aminopyridinate complexes which were dimeric for the least bulky ligand, [{Li(AmPy1)}2] or monomeric for the bulkier aminopyridinates, i.e., in [Li(AmPy2−4)(OEt2)]. One aminopyridine was deprotonated with MeMgI to give monomeric [Mg(AmPy3)I(OEt2)2]. When treated with sodium or potassium mirrors or 5% w/w Na/NaCl, over-reduction occurred, leading to the alkali metal aminopyridinates, [M(AmPy3)(η6-toluene)] (M = Na or K) or [{Na(AmPy3)}∞]. An attempted reduction of [Mg(AmPy3)I(OEt2)2] with a dimagnesium(I) compound led only to partial loss of diethyl ether and the formation of [(AmPy3)Mg(μ-I)2Mg(AmPy3)(OEt2)]. All prepared complexes have potential as ligand transfer reagents in salt metathesis reactions with metal halide complexes. [ABSTRACT FROM AUTHOR]

Effectively suppressing nonradiative recombination at the SnO2/perovskite interface is imperative for perovskite solar cells. Although the capabilities of alkali salts at the SnO2/perovskite interface have been acknowledged, the effects and optimal selection of alkali metal cations remain poorly understood. Herein, a novel approach for obtaining the optimal alkali metal cation (A‐cation) at the interface is investigated by comparatively analyzing different alkali carbonates (A2CO3; Li2CO3, Na2CO3, K2CO3, Rb2CO3, and Cs2CO3). Theoretical calculations demonstrate that A2CO3 coordinates with undercoordinated Sn and O on the surface, effectively mitigating oxygen vacancy (VO) defects with increasing A‐cation size, whereas Cs2CO3 exhibits diminished preferability owing to enhanced steric hindrance. The experimental results highlight the crucial role of Rb2CO3 in actively passivating VO defects, forming a robust bond with SnO2, and facilitating Rb+ diffusion into the perovskite layer, thereby enhancing charge extraction, alleviating deep‐level trap states and structural distortion in the perovskite film, and significantly suppressing nonradiative recombination. X‐ray absorption spectroscopy analyses further reveal the effect of Rb2CO3 on the local structure of the perovskite film. Consequently, a Rb2CO3‐treated device with aperture area of 0.14 cm2 achieves a notable efficiency of 22.10%, showing improved stability compared to the 20.11% achieved for the control device. [ABSTRACT FROM AUTHOR]

During the operation of the waste liquid incinerator, the alkali metal slag might adhere to the surface of the refractory material to form an inhomogeneous solid slag layer, causing the furnace lining to be simultaneously corroded by three phases of alkali metals: vapor, molten salt, and slag. This phenomenon intensifies the damage to the refractory material. Therefore, this paper investigates the mass transfer and permeation process, phase change process and corrosion rate of Na 2 CO 3 inside corundum refractory materials in three phases: Na vapor, molten Na 2 CO 3 and Na-slag. The results showed that alkali vapor penetrated the interior through the pores, and the NaAlO 2 and β-Al 2 O 3 generated by the reaction led to the volume expansion and microcracks. Na vapor continued to penetrate the interior along the cracks and eroded the sample, and the higher the temperature the greater Na vapor penetration. In vapor phase corrosion, the effect of corrosion time on the erosion resistance of corundum refractories is less than that of temperature, and the increase in corrosion time does not lead to the formation of additional new phases. In the molten salt corrosion experiments, it was found that the molten salt corrosion was accompanied by vapor phase corrosion at 1100 °C, and the amount of Na 2 CO 3 has a greater effect on the corroded mass than the temperature. Comparing the corrosion of refractory materials by the three phases of Na 2 CO 3 , the molten salt corrosion rate was the highest, followed by the vapor phase corrosion, and finally the slag corrosion. It is concluded that the slag layer can effectively prevent the corrosion of the refractory material by alkali metal molten salts and vapors, thus prolonging the service life of refractories. [ABSTRACT FROM AUTHOR]

Water structures at electrolyte/electrode interfaces play a crucial role in determining the selectivity and kinetics of electrochemical reactions. Despite extensive experimental and theoretical efforts, atomic-level details of ion-specific water structures on metal surfaces remain unclear. Here we show, using scanning tunneling microscopy and noncontact atomic force microscopy, that we can visualize water layers containing alkali metal cations on a charged Au(111) surface with atomic resolution. Our results reveal that Li+ cations are elevated from the surface, facilitating the formation of an ice-like water layer between the Li+ cations and the surface. In contrast, K+ and Cs+ cations are in direct contact with the surface. We observe that the water network structure transitions from a hexagonal arrangement with Li+ to a distorted hydrogen-bonding configuration with Cs+. These observations are consistent with surface-enhanced infrared absorption spectroscopy data and suggest that alkali metal cations significantly impact hydrogen evolution reaction kinetics and efficiency. Our findings provide insights into ion-specific water structures on metal surfaces and underscore the critical role of spectator ions in electrochemical processes. Water structures at the electrolyte and electrode interfaces are crucial for electrochemical reactions. Here, the authors report that alkali metal cations can modify two-dimensional water networks at charged surfaces, impacting both reaction kinetics and efficiency. [ABSTRACT FROM AUTHOR]

The structural flexibility of the perovskite blocks in the Dion-Jacobson family of layered perovskite oxides has successfully resulted in the generation of KPrNa n-2 Nb n O 3n+1 and KPrCa n-2 Nb 2 Ti n-2 O 3n+1 (n = 3, 4). The stabilization of K+ ions preferring a six coordination in the interlayer region is significant compared to the facile formation of layered perovskite oxides possessing bigger Rb+ or Cs+ ions with an eight coordination in the interlayer. The structure of the n = 3 members, KPrNaNb 3 O 10 (S. G. Cmcm ; a = 3.8858(1) Å, b = 29.6553(9) Å, c = 7.7635(3) Å) and KPrCaNb 2 TiO 10 (S. G. Cmcm ; a = 3.8634(2) Å, b = 29.4808(2) Å, c = 7.6945(5) Å) were confirmed respectively using the Rietveld and Le Bail methods utilizing the powder X-ray diffraction data. The n = 4 members, KPrNa 2 Nb 4 O 13 and KPrCa 2 Nb 2 Ti 2 O 13 are synthesized through high-temperature ceramic methods. The compounds are phase pure as confirmed from the X-ray diffraction data and were characterized by UV–visible diffuse reflectance measurements. These two-dimensional oxides also undergo facile topochemical ion-exchange and intercalation reactions and opens up several interesting possibilities. We have replaced the K+ ions in the interlayer by H+, Li+, Na+ ions and [CuCl]+ groups through low temperature reactions. The usefulness of various Dion-Jacobson layered perovskite oxides for potential photocatalytic applications has been explored by determining the optical band gaps, the valence band, and the conduction band energy levels based on the UV–visible diffuse reflectance measurements. [ABSTRACT FROM AUTHOR]

Radiative cooling pigments offer new opportunities for sustainable carbon neutrality as zero‐energy and zero‐pollution functional materials. However, it is a challenge to prepare inorganic yellow pigments simultaneously with environmentally friendly, high color value, and weather resistance. In this study, a series of alkali metal‐doped γ‐Sm2S3 yellow pigments with near‐infrared reflectance were synthesized. The doping of alkali metal ions reduced synthesis temperature of Sm2S3 from 1300°C to 1000°C. The change in energy band structure induced by alkali metal doping allows the products to exhibit modifiable colors. Typical γ‐[Na]‐Sm2S3 pigment powders have a high near‐infrared reflectance and impressive colors (b* = 78.6, C* = 77.6). Furthermore, colored films made by prepared yellow powders with polyvinylidene fluoride in certain ratios had high near‐infrared reflectance and excellent environmental weathering, resulting in an effective cooling of 4–8°C in outdoor experiments. This work expands the range of options for energy‐efficient building and yellow colorant. [ABSTRACT FROM AUTHOR]

The distribution of rare alkalis (Li, Rb, and Cs) is analyzed in spatially linked water objects of the Baikal geosystem: water of Baikal and its tributaries, underground water from boreholes and thermal springs, and the Angara River (the sole outlet), which are located in the Baikal rift zone. The rare alkali content differs significantly in some water objects, but the average and median contents are similar in the surface and deep water of Lake Baikal and the Angara River. The water of Barguzin thermal springs of the eastern shore of Lake Baikal contains the maximum amount of rare alkalis, but this affects the Baikal water insignificantly due to its natural self-cleaning and deep renewal of water during geodynamic movements. The similar rare alkali contents of Barguzin and some thermal springs of Kamchatka emphasize their indicator role in the genesis of water objects. [ABSTRACT FROM AUTHOR]

Organometallic complexes containing reactive alkali metals, such as lithium (Li), represent a promising material approach for electron injection layers and electron transport layers (EILs and ETLs) to enhance the performance of Organic Light-Emitting Diodes (OLEDs). 8-Quinolinolato Lithium (Liq) has shown remarkable potential as an EIL and ETL when conveyed in very thin films. Nevertheless, the deposition of nano-layers requires precise control over both thickness and morphology. In this work, we investigate the optical properties and morphological characteristics of Liq thin films deposited via Organic Vapor Phase Deposition (OVPD). Specifically, we present our methodology for analyzing the measured pseudodielectric function <ε(ω)> using Spectroscopic Ellipsometry (SE), alongside the nano-topography of evaporated Liq nano-layers using Atomic Force Microscopy (AFM). This information can contribute to the understanding of the functionality of this material, since ultra-thin Liq interlayers can significantly increase the operational stability of OLED architectures. [ABSTRACT FROM AUTHOR]

SYNOPSIS: The Ba-Pd EIPM facilitates the formation of monatomic Pd, adjusts the electronic environment, optimizes the Pd d-band structure, and enhances oxygen activation, enabling direct HCHO oxidation. [Display omitted] As our previous works found, alkali metals have a common promotion effect on supported noble metals catalysts for formaldehyde (HCHO) oxidation. As second-group elements, alkaline earth metals (AEMs) are neighbors to the first-group elements and share some properties in common. However, detailed investigations into the specific mechanisms underlying AEMs' effects on HCHO oxidation remain limited. In this study, we found that Ba addition showed a similar promotion effect on HCHO oxidation for Pd/TiO 2. Ba species stabilized Pd groups, improved the dispersion, and even caused a large number of monatomic-like Pd sites to appear, which may be attributed to the electronic interaction between promoter and metal (EIPM) between Ba and Pd. Besides, AEM loading had the important effect of increasing the electron density of metallic Pd nanoparticles, which further improved the ability for O 2 activation and so enhanced the mobility of chemisorbed oxygen on the catalyst surface. For Pd/TiO 2 , the HCHO oxidation path is mainly HCHO→HCOOH→HCOO→H 2 O+CO 2. By contrast, for Pd-Ba/TiO 2 , with more surface-active species, the formate intermediate was more likely to be directly oxidized into H 2 O and CO 2 , which is a more effective reaction pathway. The details of the EIPM between Pd and Ba were investigated by GPAW (DFT calculation module) in ASE (Atomic Simulation Environment). The AEM Ba acted as an electron donor and could interact with Pd d orbital electrons through BaO sp orbital electrons. Ba species were highly dispersed on the carrier due to the Ba-Ti interaction. Ba species dispersed over large areas stabilized the Pd particles and donated electrons to Pd. Therefore, adding an AEM is an efficacious strategy to improve the performance of the catalytic oxidation of HCHO. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Cu-decorated MXene is synthesized via a molten salts etching strategy. • The MXene/Cu host confines the expansion and shuttling of selenium. • Cu nanoparticles on MXene catalytic redox conversion of sodium polyselenide. • Cu nanoparticles prevents the corrosion of Cu collector improving battery stability. • Se@MXene/Cu cathode shows high-rate and long cycle performance at 50 A g−1. Sodium-selenium (Na-Se) batteries are promising energy storage systems with high energy density, high safety, and low cost. However, the huge volume change of selenium, the dissolution shuttle of polyselenides, and low selenium loading need to be solved. Herein, Cu nanoparticles decorated MXene nanosheets composite (MXene/Cu) are synthesized by etching Ti 3 AlC 2 using a molten salt etching strategy. The Se-loaded MXene/Cu (Se@MXene/Cu) electrode delivers superior electrochemical performance even with a high Se loading of ∼74.3 wt%, owing to the synergistic effect of the two-dimensional (2D) confined structure and catalytic role of the unique MXene/Cu host. Specifically, the obtained electrode provides a reversible capacity of 587.3 mAh/g at 0.2 A/g, a discharge capacity as high as 511.3 mAh/g at a high rate of 50 A/g, and still maintains a capacity of 471.9 mAh/g even after 5000 cycles based on the mass of Se@MXene/Cu. With such excellent electrochemical kinetic properties, this study highlights the importance of designing various MXene-based composites with synergistic effects of 2D confined structure and Cu catalytic center for the development of high-performance alkali metal–chalcogen battery systems. [ABSTRACT FROM AUTHOR]

In this study, Eichhornia crassipes were first cultured in eutrophic water to obtain N,P-rich plants, which were then pyrolysed in one step to N,P co-doped hard carbon, and the resulting hard carbon anode had a specific capacity of up to 336 ± 4 mAh g−1. [Display omitted] • One-step preparation of N P co-doped hard carbon. • The Na+ storage mechanism of hard carbon is systematically described by experimental and theoretical techniques. • High capacity, excellent rate capability and long-cycle stability are achieved for Na+ storage. • A new idea for the preparation of heteroatom-doped carbon. Heteroatom-doped carbon has been widely investigated as anode materials for sodium-ion batteries (SIBs). However, simplifying the preparation process and precisely controlling their microstructure to achieve excellent Na+ storage performance remain significant challenges. Therefore, in this study, high-performance N, P co-doped Na+ storage carbon anode electrode materials were prepared by one-step carbonization using N, P-rich Eichhornia crassipes (EC) as raw materials and systematically tested for their Na+ storage performance. The doping levels of N and P atoms as well as the spatial structure of the carbon material were adjusted by changing the carbonization temperature during the pyrolysis process. Among them, the anode material corresponding to 1300 °C (EC-PN1300) showed an excellent Na+ storage capacity of 336 ± 4 mAh g−1 (50 mA g−1) and excellent cycling stability (99.8 % retention after 2000 cycles). In addition, the Na+ storage mechanism of EC-PN1300 was systematically analyzed using galvanostatic intermittent titration (GITT), ex-situ XPS and in-situ Raman spectroscopy, providing accurate research directions for developing carbon anode electrode materials with superior electrochemical performance. This study not only provides some insights into the preparation of carbon anode materials in alkali metal batteries and the development of carbon materials in other fields, but also realizes the interaction between environmental protection and new energy development. [ABSTRACT FROM AUTHOR]

The photocatalytic hydrogen evolution performance of ZnIn 2 S 4 is significantly enhanced by the synergy of Na doping and loading CoSe 2 cocatalyst. [Display omitted] • ZnIn 2 S 4 was modified by doping alkali metal ions and loading CoSe 2 cocatalyst for photocatalytic hydrogen production. • Alkali metal ions doping regulate the band gap and electronic structure of ZnIn 2 S 4 , thereby improving light absorption and charge separation. • Loading CoSe 2 cocatalyst further improves the charge separation and prolongs the lifetime of charge. • CoSe 2 /Na-ZnIn 2 S 4 shows much higher H 2 evolution activity than that of pure ZnIn 2 S 4. Element doping has been demonstrated as a useful strategy to regulate the band gap and electronic structure of photocatalyst for improving photocatalytic activity. Herein, ZnIn 2 S 4 (ZIS) nanosheets were doped with alkali metal ions (Li+, Na+ or K+) by a simple solution method. Experimental characterizations reveal that alkali metal ions doping reduce the band gap, raise the conduction band position, and improve surface hydrophilicity of ZIS. In addition, theoretical calculations show that Na doping increases the electron density at valence band maximum and surrounding S atom, which is conducive to produce more electrons and effective utilization of electrons, respectively. Benefited from above factors, Na-doped ZIS (Na-ZIS) shows the highest photocatalytic hydrogen evolution performance. Furthermore, CoSe 2 cocatalyst is loaded on the surface of Na-ZIS (CS/Na-ZIS), which further improve the charge separation and prolong the lifetime of charges. As a result, the optimized CS/Na-ZIS shows a H 2 evolution rate of 4525 μmol·g−1·h−1 with an apparent quantum efficiency of 27.5 % at 420 nm, which are much higher than that of pure ZIS. This study provides an in-depth understanding of the synergistic effect of Na doping and CoSe 2 cocatalyst in ameliorating photocatalytic activity. [ABSTRACT FROM AUTHOR]

Borosilicate glasses possess excellent melting properties and high stability against chemical attack by aqueous solutions, enabling this glass family to be used in various fields. In this article, we design a novel glass network in order to achieve a chemically robust glass with a low melting temperature. Therefore, the substitution effect of Na2O by MgO, Al2O3, Li2O, and K2O on the chemical durability and melting properties of sodium aluminosilicate glass (i.e., 80SiO2‒5Al2O3‒15Na2O [mol%]) was examined using a standard hydrolytic resistance test and viscosity measurement. Interestingly, we found that the partial replacement of Na2O by Al2O3, Li2O, and K2O (i.e., 80SiO2‒5Al2O3‒15Na2O → 80SiO2‒6.5Al2O3‒9Li2O‒2.25Na2O‒2.25K2O) makes the glass network with chemical durability and melting properties comparable to those of the commercial borosilicate network, resulting in a low HCl consumption of 0.04 mL/g and working temperature of 1238°C (i.e., temperature at viscosity 104 dPa s). The structural characterizations indicate that the high chemical stability of this glass composition originates from the abundance of SiO4 tetrahedrons with three and four bridging oxygen in the glass network as well as the increase in cationic field strength of mixed alkali ions. These excellent melting properties and superior chemical durability of glass imply the possibility of using the mixed alkali metal oxides aluminosilicate glass together with the commercial borosilicate glass in the markets for numerous practical applications. [ABSTRACT FROM AUTHOR]

The O2/CO2 combustion technology is a clean coal-fired power generation technology. However, a large amount of alkali metals released during the combustion of high-alkali coal is usually an important substance that causes ash deposition, slagging and corrosion on the heating surface of boiler, which seriously affect the safe and stable operation of equipment. It is of great significance to study the release characteristics of alkali metal salts with different occurrences in the Zhundong coal under the O2/CO2 combustion atmosphere for the clean and efficient utilization of coal. Based on flame emission spectroscopy (FES), the release characteristics of different alkali metal salts in the O2/N2 and O2/CO2 atmospheres during pulverized coal combustion were studied in a metal wire mesh reactor. The results show that the combustion of volatile compounds produces a bright flame under the O2/N2 atmosphere. The combustion intensity and flame temperature of the pulverized coal in the O2/CO2 atmosphere decrease compared with that in the O2/N2 atmosphere, the ignition time is delayed, the combustion time of volatiles and coke is prolonged, and the release of Na(g) is inhibited. For NaAc, Na2CO3 and Na2SO4, the O2/CO2 atmosphere delays the decreasing time of mass concentration, so that the Na(g) in the pulverized coal enters a stable release stage from the beginning, and the mass concentration variation rate of Na(g) does not fluctuate much. However, the mass concentration variation rate of NaCl will turn negative about 4 seconds after release, resulting in a consistent decrease in the mass concentration of Na(g). At the same time, the CO2 atmosphere also causes the conversion of NaAc, NaCl and other types of salts to form Na2CO3, which is more difficult to release, and further inhibits the release process of Na(g). The main reason that the mass release rate of Na2CO3 also decreases under the O2/CO2 atmosphere is that CO2 inhibits the decomposition process of Na2CO3 to Na2O. The Na2SO4 is more difficult to release itself, so the main reason for the reduction of its mass release rate is due to the reduction of fuel combustion temperature and intensity.

Flexible organic light-emitting diodes (OLEDs) are promising light sources for biomedical applications. However, the use of these flexible devices has been restricted by their short shelf lifetimes due to poor ambient stability. Here, the fabrication of a long-lived flexible OLED is reported by replacing air-sensitive metals such as aluminum, and alkali metals used as n dopants, with silver. In addition, to achieve stable and efficient flexible OLEDs we tuned the optical cavity length to the second-order interference maximum. The device design has simple encapsulation and leads to an improvement in the air stability of flexible OLEDs which show a shelf lifetime of greater than 130 days whereas the conventional structure exhibits degradation after only 12 days. The proposed design for making flexible OLEDs demonstrates a great potential for using the devices for wearable bioelectronic applications. [ABSTRACT FROM AUTHOR]

MXene is investigated as an electrode material for different energy storage systems due to layered structures and metal‐like electrical conductivity. Experimental results show MXenes possess excellent cycling performance as anode materials, especially at large current densities. However, the reversible capacity is relatively low, which is a significant barrier to meeting the demands of industrial applications. This work synthesizes N‐doped graphene‐like carbon (NGC) intercalated Ti3C2Tx (NGC‐Ti3C2Tx) van der Waals heterostructure by an in situ method. The as‐prepared NGC‐Ti3C2Tx van der Waals heterostructure is employed as sodium‐ion and lithium‐ion battery electrodes. For sodium‐ion batteries, a reversible specific capacity of 305 mAh g−1 is achieved at a specific current of 20 mA g−1, 2.3 times higher than that of Ti3C2Tx. For lithium‐ion batteries, a reversible capacity of 400 mAh g−1 at a specific current of 20 mA g−1 is 1.5 times higher than that of Ti3C2Tx. Both sodium‐ion and lithium‐ion batteries made from NGC‐Ti3C2Tx shows high cycling stability. The theoretical calculations also verify the remarkable improvement in battery capacity within the NGC‐Ti3C2O2 system, attributed to the additional adsorption of working ions at the edge states of NGC. This work offers an innovative way to synthesize a new van der Waals heterostructure and provides a new route to improve the electrochemical performance significantly. [ABSTRACT FROM AUTHOR]

In this work, alkali metal Rb-loaded ZnO/In2O3 heterojunctions were synthesized using a combination of hydrothermal and impregnation methods. The morphology and structure of the synthesized samples were characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. The enhancement mechanism of the nitrogen dioxide gas sensing performance of the Rb-loaded ZnO/In2O3 heterojunctions was systematically investigated at room temperature using density-functional theory calculations and experimental validation. The experimental tests showed that the Rb-loaded ZnO/In2O3 sensor achieved an excellent response value of 24.2 for 1 ppm NO2, with response and recovery times of 55 and 21 s, respectively. This result is 20 times higher than that of pure ZnO sensors and two times higher than that of ZnO/In2O3 sensors, indicating that the Rb-loaded ZnO/In2O3 sensor has a more pronounced enhancement in performance for NO2. This study not only revealed the mechanism by which Rb loading affects the electronic structure and gas molecule adsorption behavior on the surface of ZnO/In2O3 heterojunctions but also provides theoretical guidance and technical support for the development of high-performance room-temperature NO2 sensors. [ABSTRACT FROM AUTHOR]

Applying lattice strain to thin films, a critical factor to tailor their properties such as stabilizing a structural phase unstable at ambient pressure, generally necessitates heteroepitaxial growth to control the lattice mismatch with substrate. Therefore, while homoepitaxy, the growth of thin film on a substrate made of the same material, is a useful method to fabricate high‐quality thin films, its application to studying strain‐induced structural phases is limited. Contrary to this general belief, here the quasi‐homoepitaxial growth of Cs and Rb thin films is reported with substantial in‐plane compressive strain. This is achieved by utilizing the alkali‐metal layer existing in bulk crystal of kagome metals AV3Sb5 (A = Cs and Rb) as a structural template. The angle‐resolved photoemission spectroscopy measurements reveal the formation of metallic quantum well states and notable thickness‐dependent quasiparticle lifetime. Comparison with density functional theory calculations suggests that the obtained thin films crystalize in the face‐centered cubic structure, which is typically stable only under high pressure in bulk crystals. These findings provide a useful approach for synthesizing highly strained thin films by quasi‐homoepitaxy, and pave the way for investigating many‐body interactions in Fermi liquids with tunable dimensionality. [ABSTRACT FROM AUTHOR]

There are 2 main problems with the current periodic table: artificial breaks from a given noble gas to the next alkali metal (along with the common protrusion of the "f" block) and hydrogen placed in the alkali group, although this gas also exhibits halogen properties. This paper proposes arranging chemical elements in a square spiral with hydrogen at the centre. This element is also above lithium but passes above fluorine to connect with helium, representing its dual alkali and halogen nature effectively. Then the spiral moves outwards in a counter-clockwise direction, avoiding artificial breaks and following the natural direction of reading for the "s" and "p" blocks elements placed at the bottom of the spiral. Furthermore, this proposed square spiral improves upon previous Janet´s and Benfey´s representations with a more regular shape to draw, an effective depiction of the dual nature of hydrogen, and easily identifiable orbital blocks without the need for protrusions. [ABSTRACT FROM AUTHOR]

Porous hard carbon with good cycling durability attracts much attention in the application of sodium ions batteries as anode material, but the commonly used alkali metal ion-activation strategy with complex processes still renders its development. Herein, a simple and scalable method is proposed to synthesize hierarchical porous hard carbon. Benefitting from the efficient self-activation strategy, the hierarchical micro–mesoporous hard carbon (MMHC) with large interlayer distance possesses high specific surface area of 704.1 m2 g−1, which can provide shorter ionic diffusion path and much more accessible electrochemical active sites in the carbonaceous structure and then lead to fast sodium ion diffusivity kinetics (3.5 × 10–9 cm2 s−1). In consequence, MMHC electrode delivers high specific capacity of 214.3 mAh g−1 at 50 mA g−1, 118.3 mAh g−1 at 500 mA g−1 after 1000 cycles and 47.4 mAh g−1 even at 4000 mA g−1. Notably, the capacity contribution ratio from low-voltage range is enhanced with engineering micro–mesoporous structure (from 28.5% for HC to 37.7% for MMHC). Promisingly, the hierarchical micro–mesoporous hard carbon holds great potential in commercial sodium ions batteries. [ABSTRACT FROM AUTHOR]

This paper reports on computational results of continuum spectra of atomic lithium in white-dwarf-strength magnetic fields. The adiabatic-basis-expansion method with R -matrix propagation has been used to study photoionization of magnetized alkali metal atoms. The R -matrix propagation technique and the two-dimensional matching scheme were utilized to obtain wavefunctions of the continuum states. Cross-sections of photoionization are calculated for lithium atoms in magnetic fields. Continuum spectra for its various bound-free transitions in magnetic white dwarf stars are presented as a function of field strengths ranging from 11.75 to 117.50 MG. Comparison is made between continuum spectra of diamagnetic hydrogen and lithium atoms. The comparison shows good agreement or remarkable difference for final continuum states with different symmetries in the photoionization processes concerned. A detailed analysis has been performed to understand the obtained results. The good agreement displayed manifests the reliability of the extended adiabatic-basis-expansion method. This method is suited to produce a large number of photoionization cross-section data for alkali metal atoms in a strong magnetic field, and therefore can serve as a tool to simulate continuum spectra observed in the atmospheres of magnetic white dwarfs with alkali metal atoms. [ABSTRACT FROM AUTHOR]

Alkali metals (Li, Na, and K) are deemed as the ideal anode materials for next-generation high-energy-density batteries because of their high theoretical specific capacity and low redox potentials. However, alkali metal anodes (AMAs) still face some challenges hindering their further applications, including uncontrollable dendrite growth and unstable solid electrolyte interphase during cycling, resulting in low Coulombic efficiency and inferior cycling performance. In this regard, designing 3D current collectors as hosts for AMAs is one of the most effective ways to address the above-mentioned problems, because their sufficient space could accommodate AMAs' volume expansion, and their high specific surface area could lower the local current density, leading to the uniform deposition of alkali metals. Herein, we review recent progress on the application of 3D Cu-based current collectors in stable and dendrite-free AMAs. The most widely used modification methods of 3D Cu-based current collectors are summarized. Furthermore, the relationships among methods of modification, structure and composition, and the electrochemical properties of AMAs using Cu-based current collectors, are systematically discussed. Finally, the challenges and prospects for future study and applications of Cu-based current collectors in high-performance alkali metal batteries are proposed. [ABSTRACT FROM AUTHOR]

Various copper-related defects in the absorption layer have been a key factor impeding the enhancement of the efficiency of Cu2ZnSn(S,Se)4 (CZTSSe) solar cells. Alkali metal doping is considered to be a good strategy to ameliorate this problem. In this article, Rb-doped CZTSSe (RCZTSSe) thin films were synthesized using the sol–gel technique. The results show that the Rb atom could successfully enter into the CZTSSe lattice and replace the Cu atom. According to SEM results, a moderate amount of Rb doping aided in enhancing the growth of grains in CZTSSe thin films. It was proven that the RCZTSSe thin film had the densest surface morphology and the fewest holes when the doping content of Rb was 2%. In addition, Rb doping successfully inhibited the formation of CuZn defects and correlative defect clusters and promoted the electrical properties of RCZTSSe thin films. Finally, a remarkable power conversion efficiency of 7.32% was attained by the champion RCZTSSe device with a Rb content of 2%. Compared with that of un-doped CZTSSe, the efficiency improved by over 30%. This study offers new insights into the influence of alkali metal doping on suppressing copper-related defects and also presents a viable approach for improving the efficiency of CZTSSe devices. [ABSTRACT FROM AUTHOR]

Single-layer blue phosphorus (SLBP) has displayed charming photoelectric performances, but its property in hydrogen storage is not outstanding due to the weak interactions. To expand the application of SLBP in hydrogen storage, we attempt to screen SLBP-based materials with stable structures and strong polarity using density functional theory by doping lightweight elements and grafting alkali metal atoms. The simulation results indicate that the lightweight elements (B, C, N, O and F) doped SLBP systems have more stable structures due to the strong orbital interaction than pure SLBP, and exhibit electron deficient characteristics. Compared to the pure SLBP, the H 2 adsorption energies of the doped systems improve and range from 0.05 to 0.09 eV, but it still cannot meet the requirements of ideal hydrogen storage. Therefore, the lightweight element doped SLBP systems are further grafted by Li atom. Under the synergistic effect of doping lightweight elements and grafting Li atoms, H 2 molecules are strongly polarized, and the corresponding adsorption energies of H 2 reach to 0.16, 0.26, 0.28, 0.30, and 0.10 eV, respectively. It is worth emphasizing in the C-doped SLBP system that the hydrogen storage capacity of reaches 5.53 wt% for each Li atom adsorbs one hydrogen molecule and the corresponding adsorption energy is 0.23 eV/H 2 when the ratio of C to P atoms increases to 6:26. For each Li atom adsorbs two hydrogen molecules in the same hydrogen storage system, the hydrogen storage capacity reaches 10.48 wt% with 0.18 eV/H 2 adsorption energy. We hope these results can provide theoretical basis and scientific guidance for searching for SLBP-based materials with excellent hydrogen storage performances at ambient temperature. [ABSTRACT FROM AUTHOR]

The carbon dioxide reduction reaction (CO2RR) is one of the most promising solutions for realizing carbon neutralization via converting the emitted CO2 into value‐added chemicals. The CC coupling step for CO dimerization is the rate‐determining step for C2 pathways, which have not been thoroughly investigated. Herein, the direct cation stabilization effects on CO dimerization for *OCCO formation on the representative Cu(100) and Pt(100) surfaces are investigated. Density functional theory calculations show that the presence of alkali metal ions plays a vital role in promoting the coupling of *CO monomers on both metal surfaces, where Cu shows a stronger stabilization effect. More importantly, a strong linear correlation (R2 ≈ 0.9) between the dimer stabilization energy and the reaction energy is revealed for the first time, which is a promising indicator for the selectivity of C2 pathways. Further investigations on electronic structures reveal that the promoting effect on *OCCO formation is strongly related to the negative charges of the molecules, in which the negative charge accumulation is favored by the directional electron transfer due to the chemisorption of *OCCO on Cu(100) surface. This work offers insights into the understanding of CC coupling reactions for CO2RR mechanisms. [ABSTRACT FROM AUTHOR]

Co-thermal chemical conversion of coal and biomass is one of the important ways to realize efficient and clean utilization of coal. In this study, a typical Ningdong coal-Yangchangwan bituminous coal and cow manure were used to study the synergistic effect of intrinsic alkali, alkaline earth metals (AAEM) and organic matter on the co-gasification of coal and biomass by thermogravimetry analyzer (TG). The results showed that AAEM had obvious synergistic promotion effect on the gasification of a bituminous coal-cow manure mixture in the isothermal gasification (1000 ℃), whereas the organic matter will show the opposite effect on the process. To further investigate the effect of organic matter on the gasification process, the influence of organic matter on non-isothermal (25-1000 ℃) gasification reaction was investigated with heating rate of 10 ℃ /min, the kinetic parameters of the gasification reaction were obtained by Coats-Redfern method. The increase of biomass mass fraction in the sample facilitates the migration of alkali metals from the material to the solid phase. The possible mechanism of the synergistic effect of intrinsic AAEM/organic matter on the co-gasification process was proposed. [ABSTRACT FROM AUTHOR]

Summary: Plant yields heavily depend on proper macro‐ and micronutrient supply from the soil. In the leaf cells, nutrient ions fulfill specific roles in biochemical reactions, especially photosynthesis housed in the chloroplast. Here, a well‐balanced ion homeostasis is maintained by a number of ion transport proteins embedded in the envelope and thylakoid membranes. Ten years ago, the first alkali metal transporters from the K+ EFFLUX ANTIPORTER family were discovered in the model plant Arabidopsis. Since then, our knowledge about the physiological importance of these carriers and their substrates has greatly expanded. New insights into the role of alkali ions in plastid gene expression and photoprotective mechanisms, both prerequisites for plant productivity in natural environments, were gained. The discovery of a Cl− channel in the thylakoid and several additional plastid alkali and alkali metal transport proteins have advanced the field further. Nevertheless, scientists still have long ways to go before a complete systemic understanding of the chloroplast's ion transportome will emerge. In this Tansley review, we highlight and discuss the achievements of the last decade. More importantly, we make recommendations on what areas to prioritize, so the field can reach the next milestones. One area, laid bare by our similarity‐based comparisons among phototrophs is our lack of knowledge what ion transporters are used by cyanobacteria to buffer photosynthesis fluctuations. See also the Commentary on this article by Kuang & Romand, 243: 506–508. [ABSTRACT FROM AUTHOR]

The urgent need to shift from non-renewable to renewable energy sources has caused widespread interest in photovoltaic technologies that allow us to harness readily available and sustainable solar energy. In the past decade, polymer solar cells (PSCs) and perovskite solar cells (Per-SCs) have gained attention owing to their low price and easy fabrication process. Charge transport layers (CTLs), transparent conductive electrodes (TCEs), and metallic top electrodes are important constituents of PSCs and Per-SCs, which affect the efficiency and stability of these cells. Owing to the disadvantages of current materials, including instability and high cost, the development of alternative materials has attracted significant attention. Owing to their more flexible physical and chemical characteristics, ternary oxides are considered to be appealing alternatives, where ATiO3 materials—a class of ternary perovskite oxides—have demonstrated considerable potential for applications in solar cells. Here, we have employed calculations based on the density functional theory to study the structural, optoelectronic, and magnetic properties of ATiO3 (A=Li, Na, K, Rb, and Cs) in different crystallographic phases to determine their potential as PSCs and Per-SCs materials. We have also determined thermal and elastic properties to evaluate their mechanical and thermal stability. Our calculations have revealed that KTiO3 and RbTiO3 possess similar electronic properties as half-metallic materials, while LiTiO3 and CsTiO3 are metallic. Semiconductor behavior with a direct band gap of 2.77 eV was observed for NaTiO3, and calculations of the optical and electronic properties predicted that NaTiO3 is the most appropriate candidate to be employed as a charge transfer layer (CTL) and bottom transparent conducting electrode (TCE) in PSCs and Per-SCs, owing to its transparency and large bandgap, whereas NaTiO3 also provided superior elastic and thermal properties. Among the metallic and half-metallic ATiO3 compounds, CsTiO3 and KTiO3 exhibited the most appropriate features for the top electrode and additional absorbent in the active layer, respectively, to enhance the performance and stability of these cells. [ABSTRACT FROM AUTHOR]

The electroanalytical behavior of SnSx (x = 1, 2) encapsulated into a carbon phase was studied using the galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS). These techniques are widely utilized in battery systems to investigate the diffusion of alkali metal cations in anode and cathode materials depending on the concentration of ions in the host material. Here, we report different calculation methods showing how the applied model affects the derived diffusion coefficient. The calculated value of the apparent chemical diffusion coefficient of sodium ions ( D N a + ) is in the range of 1 × 10−10 to 1 × 10−15 cm2/s depending on the technique, mathematical protocol, geometry of the electrode material, and applied potential. [ABSTRACT FROM AUTHOR]

Despite the discovery of a series of fullerenes and a handful of noncarbon clusters with the typical topology of I h-C60, the smallest fullerene with a large degree of curvature, C20, and its other-element counterparts are difficult to isolate experimentally. In coinage metal nanoclusters (NCs), the first all-gold fullerene, Au32, was discovered after a long-lasting pursuit, but the isolation of similar silvery fullerene structures is still challenging. Herein, we report a flying saucer-shaped 102-nuclei silver NC (Ag102) with a silvery fullerene kernel of Ag32, which is embraced by a robust cyclic anionic passivation layer of (KPO4)10. This Ag32 kernel can be viewed as a non-centered icosahedron Ag12 encaged into a dodecahedron Ag20, forming the silvery fullerene of Ag12@Ag20. The anionic layer (KPO4)10 is located at the interlayer between the Ag32 kernel and Ag70 shell, passivating the Ag32 silvery fullerene and templating the Ag70 shell. The t BuPhS− and CF3COO− ligands on the silver shell show a regioselective arrangement with the 60 t BuPhS− ligands as expanders covering the upper and lower of the flying saucer and 10 CF3COO− as terminators neatly encircling the edges of the structure. In addition, Ag102 shows excellent photothermal conversion efficiency (η) from the visible to near-infrared region (η  = 67.1% ± 0.9% at 450 nm, 60.9% ± 0.9% at 660 nm and 50.2% ± 0.5% at 808 nm), rendering it a promising material for photothermal converters and potential application in remote laser ignition. This work not only captures silver kernels with the topology of the smallest fullerene C20, but also provides a pathway for incorporating alkali metal (M) into coinage metal NCs via M-oxoanions. [ABSTRACT FROM AUTHOR]

The South China Block, a region renowned for its extensive granite distribution and rich metal deposits, serves as a natural laboratory for the study of granite-related mineralization. This research focuses on the Tongtianmiao granite pluton, which is located at the intersection of the Qin-Hang and Nanling metallogenic belts and has been confirmed as a significant lithium mineral resource. Despite its discovery and ongoing development, the lithium-rich Tongtianmiao pluton has been understudied, particularly concerning its petrogenesis, which has only recently come to the forefront of scientific inquiry. By integrating an array of petrogeochemical data with geochronological studies derived from zircon and monazite dating, this study provides insights into the magmatic processes related to lithium enrichment in the Tongtianmiao granites. The Tongtianmiao granites are classified as A-type granites characterized by high SiO2 contents (69.18–78.20 wt.%, average = 74.08 wt.%), K2O + Na2O contents (4.59–8.34 wt.%, average = 6.86 wt.%), A/CNK > 1.2, and low concentrations of Ca, Mg, and Fe. These granites are enriched in alkali metals such as Li, Rb, and Cs but are significantly depleted in Ba, Sr, and Eu. They show no significant fractionation of light or heavy rare-earth elements but present characteristic tetrad effects. A finding of this study is the identification of multiple ages from in situ zircon U–Pb dating, which implies a prolonged history of magmatic activity. However, given the high uranium content in zircons, which could render U–Pb ages unreliable, emphasis is placed on the monazite U–Pb ages. These ages cluster at approximately 172.1 ± 1.1 Ma and 167.9 ± 1.6 Ma, indicating a Middle Jurassic period of granite formation. This timing correlates with the retreat of the Pacific subduction plate and the associated NE-trending extensional fault activity, which likely provided favorable conditions for lithium enrichment. The study concluded that the Tongtianmiao granites were formed through partial melting of crustal materials and subsequent underplating by mantle-derived materials, and were contaminated by strata materials. This process resulted in the formation of highly differentiated granite through magmatic differentiation and external forces. These findings have significant implications for understanding the petrogenesis of lithium-rich granites and are expected to inform future exploration endeavors in the Tongtianmiao pluton. [ABSTRACT FROM AUTHOR]

The solid polymer electrolyte (SPE) field has traditionally struggled with sufficiently high cation conduction at room temperature. The reason for this is that ion transport is usually coupled to polymer chain mobility and as such is strongly temperature dependent. The diversification of battery technologies from Li‐ion into Na‐ and K‐ion batteries has revived efforts in the 80s and 90s to develop a broad conceptional understanding and to find overarching trends of the ion transport properties of SPEs based on Group 1 elements, Li+, Na+, K+, Rb+ and Cs+ (i. e. beyond Li). This development brings its own set of challenges, starting from additional constraints to measure heavier cations. With a clearer aim towards tangible battery applications, particularly electrochemical stability and interphase formation, and together with a rising sensibility of sustainability aspects, other parameters have gained more relevance and opened new vectors of research. The associated scientific challenges and recent developments of Group 1 based SPEs shall be reviewed. [ABSTRACT FROM AUTHOR]

Recently, scientists have been developing sustainable processes, and in this context, mechanochemistry is commonly associated with green chemistry for its ability to reduce waste generation from chemical reactions. The well-known acetate complex, diacetate bis(triphenylphosphine) ruthenium(II) [Ru(OAc)2(PPh3)2], is a versatile precursor for preparing active complexes for several catalytic reactions. This report presents an efficient and straightforward manual grinding protocol for the sustainable synthesis of ruthenium carboxylate complexes starting from the commercially available [RuCl2(PPh3)3] and metal carboxylates. This work represents a novel and preliminary investigation into carboxylate precursors' alternative solventless synthesis route based on manual grinding. To our knowledge, this is the first time [Ru(OAc)2(PPh3)2] has been prepared via a mechanochemical procedure. The synthesis method has also been investigated for other alkali metal carboxylates and yields ranging from 30 to 80% were obtained. A comparison of sustainability and environmental impact between conventional solution synthesis and the grinding route has been carried out using the E-factor and Mass Productivity. While for the acetate complex E-factor and MP were only slightly better compared with the solvent method (3 vs. 4 for E-factor and ~6 vs. 5 for MP), for benzoate higher results were found (1 vs. ~4 for E-factor and 10 vs. 5 for MP). [ABSTRACT FROM AUTHOR]

Electride possesses electrons localized at interstitial sites without attracting nuclei. It brings outstanding material properties not only originating from its own loosely bounded characteristics but also serving as a quasiatom, which even chemically interacts with other elemental ions. In elemental metals, electride transitions have been reported in alkali metals where valence electrons can easily gain enough kinetic energy to escape nuclei. However, there are few studies on transition metals. Especially iron, the key element of human technology and geophysics, has not been studied in respect of electride formation. In this study, it is demonstrated that electride formation drives the superionic state in iron hydride under high‐pressure conditions of the earth's inner core. The electride stabilizes the iron lattice and provides a pathway for hydrogen diffusion by severing the direct interaction between the metal and the volatile element. The coupling between lattice stability and superionicity is triggered near 100 GPa and enhanced at higher pressures. It is shown that the electride‐driven superionicity can also be generalized for metal electrides and other rocky planetary cores by providing a fundamental interaction between the electride of the parent metal and doped light elements. [ABSTRACT FROM AUTHOR]

Metals are integral components of the natural environment, and their presence in the food supply is inevitable and complex. While essential metals such as sodium, potassium, magnesium, calcium, iron, zinc, and copper are crucial for various physiological functions and must be consumed through the diet, others, like lead, mercury, and cadmium, are toxic even at low concentrations and pose serious health risks. This study comprehensively analyzes the presence, importance, and consequences of metals in the food chain. We explore the pathways through which metals enter the food supply, their distribution across different food types, and the associated health implications. By examining current regulatory standards for maximum allowable levels of various metals, we highlight the importance of ensuring food safety and protecting public health. Furthermore, this research underscores the need for continuous monitoring and management of metal content in food, especially as global agricultural and food production practices evolve. Our findings aim to inform dietary recommendations, food fortification strategies, and regulatory policies, ultimately contributing to safer and more nutritionally balanced diets. [ABSTRACT FROM AUTHOR]

Na1.36(Si0.86Ga0.14)2As2.98 and Li1.5Ga0.9Si3.1As4 were synthesized by heating mixtures of the elements at 950 °C. The crystal structures were determined by single crystal X-ray diffraction (Na1.36(Si0.86Ga0.14)2As2.98: I41/a, Z = 100, a = 19.8772(4) Å, c = 37.652(1) Å; Li1.5Ga0.9Si3.1As4: C2/c, Z = 8, a = 10.8838(6) Å, b = 10.8821(6) Å, c = 13.1591(7) Å). Na1.36(Si0.86Ga0.14)2As2.98 crystallizes similar to NaSi2P3 with interpenetrating networks of vertex-sharing T4 and T5 supertetrahedra. Gallium substitution at the silicon sites increases the charge of the cluster network, which is compensated for by a 36% higher sodium content. Since in contrast to NaSi2P3, all sodium sites are now fully occupied, there is no significant ion mobility, as indicated by 23Na-NMR. Consequently, the total sodium-ion conductivity of Na1.36(Si0.86Ga0.14)2As2.98 amounts to only 1.6(1) × 10−7 S cm−1 and is therefore three orders of magnitude lower than in NaSi2P3. Li1.5Ga0.9Si3.1As4 crystallizes in a new structure type with layers of edge-sharing (Si1−xGax)As4 tetrahedra alternating with layers that contain infinite Sin zigzag chains. Lithium ions reside in channels between the chains, and thus, the structure does not provide three dimensional pathways for ion conduction and the measured total Li-ion conductivity amounts to only 1.3(1) × 10−7 S cm−1. [ABSTRACT FROM AUTHOR]

The present work employs density functional theory to explore the structural, optoelectronic, and thermoelectric attributes of the halide-based double perovskite A2GeSnF6 (A = K, Rb, and Cs) compounds. The stable phonon dispersion spectrum affirms dynamical stability, whereas the enthalpy of formation and tolerance factor evaluated collectively verify structural stability. Considering the Tran Blaha modified Becke Johnson potentials (mBJ), the predicted direct band gaps along the symmetry point are 3.19 eV for K2GeSnF6, 3.16 eV for Rb2GeSnF6 and 3.12 eV Cs2GeSnF6. According to an in-depth examination of the optoelectronic features, A2GeSnF6 (A = K, Rb, and Cs), double perovskites are assuring contenders for optoelectronic devices due to their suitable bandgap. The extremely high figure of merit values (0.94–0.97) obtained from the numerical calculation of power factor and thermal conductivity suggest the intriguing prospects of these compositions for thermoelectric devices. These studies offer a perceptive comprehension of the materials for their potential applications in the future. [ABSTRACT FROM AUTHOR]

In an effort to obtain a novel cyan‐emitting phosphor, the [K1‐xRbx]3GdSi2O7: yCe3+ materials (x = 0, 0.1, 0.2, 0.3, 0.4, y = 0, 0.005, 0.01, 0.02, 0.03, 0.04) are synthesized via a solid‐state reaction pathway, and their crystal structure and luminescence behaviors are studied systematically. The chemical substitution of Rb+ in the K+ sites can enlarge the K3GdSi2O7 host lattice and help to the blue‐shifting of emission band of Ce3+ ions due to the decreased crystal field splitting effect. It is also confirmed that the Ce3+ ions tend to enter [Gd1O6] and [Gd2O6] polyhedrons simultaneously. Consequently, the [K0.7Rb0.3]3GdSi2O7: Ce3+ phosphor yields a broadband cyan emission centered at 492 nm with the full width at half maximum (FWHM) of ∼115 nm upon 365 nm excitation. The optimal concentration of Ce3+ dopant is determined to be 0.01, and the concentration quenching effect can be attributed to the dipole−dipole interactions. The white light emitting diode (WLED) device fabricated by employing the discovered [K0.7Rb0.3]3GdSi2O7: 0.01Ce3+ phosphor displays a high color rendering index (Ra = 91.7) and a low correlated color temperature (CCT = 3749 K). This work may promote the development of cyan phosphors for near ultraviolet‐converted WLEDs with high performance. [ABSTRACT FROM AUTHOR]

Owing to the important role of and increasing demand for lithium resources, lithium extraction is crucial. The use of molecular extractants is a promising strategy for selective lithium recovery, in which the interaction between lithium and the designed extractant can be manipulated at the molecular level. Herein, we demonstrate that anion receptors of tripodal hexaureas can selectively extract Li2SO4 solids into water containing DMSO (0.8% water) compared to other alkali metal sulfates. The hexaurea receptor with terminal hexyl chains displays the best Li+ extraction selectivity at 2-fold over Na+ and 12.5-fold over K+. The driving force underpinning selective lithium extraction is due to the combined interactions of Li+-SO42− electrostatics and the ion–dipole interaction of the lithium–receptor (carbonyl groups and N atoms); the latter was found to be cation size dependent, as supported by computational calculations. This work indicates that anion binding receptors could drive selective cation extraction, thus providing new insights into the design of receptors for ion recognition and separation. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS2), a typical layered material, has important applications in various fields, such as optoelectronics, catalysis, electronic devices, sensors, and supercapacitors. Extensive research has been carried out on few-layered MoS2 in the field of electrochemistry due to its large specific surface area, abundant active sites and short electron transport path. However, the preparation of few-layered MoS2 is a significant challenge. This work presents a simple one-pot hydrothermal method for synthesizing few-layered MoS2. Furthermore, it investigates the exfoliation effect of different amounts of sodium borohydride (NaBH4) as a stripping agent on the layer number of MoS2. Na+ ions, as alkali metal ions, can intercalate between layers to achieve the purpose of exfoliating MoS2. Additionally, NaBH4 exhibits reducibility, which can effectively promote the formation of the metallic phase of MoS2. Few-layered MoS2, as an electrode for supercapacitor, possesses a wide potential window of 0.9 V, and a high specific capacitance of 150 F g−1 at 1 A g−1. This work provides a facile method to prepare few-layered two-dimensional materials for high electrochemical performance. [ABSTRACT FROM AUTHOR]

The Weilasituo Li–polymetallic deposit, located on the western slope of the southern Great Xing'an Range in the eastern Central Asian Orogenic Belt, is hosted by quartz porphyry with crypto-explosive breccia-type Li mineralisation atop and vein-type Sn-Mo-W-Zn polymetallic mineralisation throughout the breccia pipe. This study introduces new data on multistage quartz and mica in situ trace elements; the study was conducted using laser ablation inductively coupled plasma mass spectrometry and 40Ar/39Ar dating of zinnwaldite to delineate the metallogenic age and genesis of Li mineralisation. Zinnwaldite yields a plateau age of 132.45 ± 1.3 Ma (MSWD = 0.77), representing Early Cretaceous Li mineralisation. Throughout the magmatic–hydrothermal process, quartz trace elements showed Ge enrichment. Li, Al, and Ti contents decreased, with Al/Ti and Ge/Ti ratios increasing, indicating increased magmatic differentiation, slight acidification, and cooling. Mica's rising Li, Rb, Cs, Mg, and Ti contents and Nb/Ta ratio, alongside its falling K/Rb ratio, indicate the magma's ongoing crystallisation differentiation. Fractional crystallisation primarily enriched Li, Rb, and Cs in the late melt. Mica's high Sc, V, and W contents indicate a high fO2 setting, with a slightly lower fO2 during zinnwaldite formation. Greisenisation observed Zn, Mg, and Fe influx from the host rock, broadening zinnwaldite distribution and forming minor Zn vein orebodies later. Late-stage fluorite precipitation highlights a rise in F levels, with fluid Sn and W levels tied to magma evolution and F content. In summary, the Weilasituo Li–polymetallic deposit was formed in an Early Cretaceous extensional environment and is closely related to a nearby highly differentiated Li-F granite. During magma differentiation, rare metal elements such as Li and Rb were enriched in residual melts. The decrease in temperature and the acidic environment led to the precipitation of Li-, Rb-, and W-bearing minerals, and the increased F content in the late stage led to Sn enrichment and mineralisation. Fluid metasomatism causes Zn, Mg, and Fe in the surrounding rock to enter the fluid, and Zn is enriched and mineralised in the later period. [ABSTRACT FROM AUTHOR]

Ultra-flat, ultra-thin alkali antimonide photocathodes with high crystallinity can exhibit high quantum efficiency and low mean transverse energy of outgoing electrons, which are essential requirements for a variety of applications for photocathode materials. Here, we investigate the growth of Cs3Sb on graphene-coated 4H–SiC (Gr/4H–SiC), 3C–SiC, and Si3N4 substrates. Sb is deposited using pulsed laser deposition, while Cs is deposited thermally and simultaneously. We demonstrate, employing x-ray analysis and quantum efficiency measurements, that this growth method yields atomically smooth Cs3Sb photocathodes with a high quantum efficiency (>10%), even in the ultra-thin limit (<30 nm). For the Si3N4 substrate, film growth is shown to be polycrystalline, while films grown on Gr/4H–SiC show a high degree of ordering with signs of epitaxy. [ABSTRACT FROM AUTHOR]

Updated formation and structure models of Jupiter predict a metal-poor envelope. This is at odds with the two to three times solar metallicity measured by the Galileo probe. Additionally, Juno data imply that water and ammonia are enriched. Here, we explore whether Jupiter could have a deep radiative layer separating the atmosphere from the deeper interior. The radiative layer could be caused by a hydrogen-transparency window or depletion of alkali metals. We show that heavy-element accretion during Jupiter's evolution could lead to the desired atmospheric enrichment and that this configuration would be stable over billions of years. The origin of the heavy elements could be cumulative small impacts or one large impact. The preferred scenario requires a deep radiative zone, due to a local reduction of the opacity at ∼2000 K by ∼90%, which is supported by Juno data, and vertical mixing through the boundary with an efficiency similar to that of molecular diffusion (D ≲ 10−2 cm2 s−1). Therefore, most of Jupiter's molecular envelope could have solar composition while its uppermost atmosphere is enriched with heavier elements. The enrichment likely originates from the accretion of solid objects. This possibility resolves the long-standing mismatch between Jupiter's interior models and atmospheric composition measurements. Furthermore, our results imply that the measured atmospheric composition of exoplanets does not necessarily reflect their bulk compositions. We also investigate whether the enrichment could be due to the erosion of a dilute core and show that this is highly unlikely. The core-erosion scenario is inconsistent with evolution calculations, the deep radiative layer, and published interior models. [ABSTRACT FROM AUTHOR]

Declining the sintering temperature of enamel coatings is traditionally by reducing the content of network-forming agents (such as SiO 2) and increasing the content of flux (for example, alkali metal oxides), which will lower the density of the [- Si - O -] network structure, and adversely affect the corrosion resistance of enamel coatings. To ensure a low sintering temperature of enamel coatings as much as possible under a high SiO 2 content, it is essential to develop novel enamel coating formulas. However, abundant compositions of enamel coatings cause enormous verification workloads. To address this issue, this paper establishes a relational model of the compositions of enamel coatings and the sintering temperature using the back propagation (BP) neural network algorithm and proposes a formula that meets the requirement of lower the sintering temperature under a high SiO 2 content. When the SiO 2 content is 55 %, the sintering temperature can be diminished to around 400 °C. Furthermore, the influences of common enamel components on the sintering temperature are identified in this paper using the sensitivity algorithm. The obtained general law of formulas is that the total weight value of the formula at low sintering temperatures should be around −0.3. This paper can provide valuable theoretical guidance for subsequent research and expand the application range of enamel coatings. [ABSTRACT FROM AUTHOR]

Combining biomass co-firing with oxy-fuel combustion is a promising Bioenergy with Carbon Capture and Storage (BECCS) technology. It has the potential to achieve a large-scale reduction in carbon emissions from traditional power plants, making it a powerful tool for addressing global climate change. However, mercury in the fuel can be released into the flue gas during combustion, posing a significant threat to the environment and human health. More importantly, mercury can also cause the fracture of metal equipment via amalgamation, which is a major risk for the system. Therefore, compared to conventional coal-fired power plants, the requirements for the mercury concentration in BECCS systems are much stricter. This article reviews the latest progress in mercury control under oxy-fuel biomass co-firing conditions, clarifies the impact of biomass co-firing on mercury species transformation, reveals the influence mechanisms of various flue gas components on elemental mercury oxidation under oxy-fuel combustion conditions, evaluates the advantages and disadvantages of various mercury removal methods, and finally provides an outlook for mercury control in BECCS systems. Research shows that after biomass co-firing, the concentrations of chlorine and alkali metals in the flue gas increase, which is beneficial for homogeneous and heterogeneous mercury oxidation. The changes in the particulate matter content could affect the transformation of gaseous mercury to particulate mercury. The high concentrations of CO2 and H2O in oxy-fuel flue gas inhibit mercury oxidation, while the effects of NOx and SO2 are dual-sided. Higher concentrations of fly ash in oxy-fuel flue gas are conducive to the removal of Hg0. Additionally, under oxy-fuel conditions, CO2 and metal ions such as Fe2+ can inhibit the re-emission of mercury in WFGD systems. The development of efficient adsorbents and catalysts is the key to achieving deep mercury removal. Fully utilizing the advantages of chlorine, alkali metals, and CO2 in oxy-fuel biomass co-firing flue gas will be the future focus of deep mercury removal from BECCS systems. [ABSTRACT FROM AUTHOR]

The AV3Sb5 prototype kagome materials have been demonstrated as a versatile platform for exploring exotic properties in condensed matter physics, including charge density waves, superconductivity, non-trivial electron topology, as well as topological superconductivity. Here we identify that ANb3Bi5 (A = K, Rb, Cs) exhibit non-trivial coexisting superconductivity and topological properties via first-principles calculations. The negative formation energy and the absence of imaginary phonon dispersion demonstrate both thermodynamics and dynamics stabilities of ANb3Bi5 (A = K, Rb, Cs) under ambient conditions. By analytically solving the Allen-Dynes-modified McMillan formula, the superconducting transition temperatures are predicted to be 2.11, 2.15 and 2.21 K for KNb3Bi5, RbNb3Bi5, and CsNb3Bi5, respectively. More importantly, the kagome materials proposed here can be classified into Z 2 topological metals due to the non-trivial topological index and the obvious surface states around the Fermi level. Such coexistence of superconductivity and non-trivial band characters in ANb3Bi5 (A = K, Rb, Cs) offer us more insights to study the relationship between superconductivity and topological properties, and to design innate topological superconductors. [ABSTRACT FROM AUTHOR]

The paper presented delivers the proof for one of the possible solutions to the so-called medium-temperature gap—the lack of electrolytic systems able to efficiently work in a temperature range spanning from 200 to 450 °C. Regardless of the progress made in this field, the commercially available systems are still operating either at close to ambient temperatures, where hydrogen purity requirements are a significant limit, or above ca. 600 °C, where they suffer from increased corrosion and excessive thermal stresses occurring during startup and shutdown. Alkali metal orthoborates (M3BO3 M = Li, Na, K, or the mixture of these), in contrast to commercially used tetra-(M2B4O7) and meta-(MBO2) borates of these metals, are compounds with relatively poorly understood structure and physicochemical properties. The possibility of their application as an electrolyte in a fuel cell is a relatively new idea and has been preliminary reported. Therefore, an extended phase-focused analysis of the materials applied was needed to re-optimize both the synthetic strategy and the application route. Results of PXRD and FT-IR investigations showed, on the one hand, a complicated multi-phase structure, including the main orthoborate phase, as well as the presence of additional borate-based phases, including boric oxoacid. On the other hand, DTA tests proved not only that their melting temperatures are lower than these characteristics for the tetra- and meta-counterparts, but also that cation mixing leads to a subsequent decrease in this important functional parameter of the materials studied. [ABSTRACT FROM AUTHOR]