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Breaking the intrinsic rule of semiconductors that conductivity increases with increase of temperature and realizing a dramatic dropping of conductivity at high temperature may arouse new intriguing applications, such as circuit overload or over‐temperature protecting. This goal has now been achieved through T‐type electron‐transfer photochromism of one organic semiconductor assembled by intermolecular cation⋅⋅⋅π interactions. Conductivity of the viologen‐based model semiconductor (H2bipy)(Hox)2 (H2bipy=4,4′‐bipyridin‐1,1′‐dium; ox=oxalate) increased by 2 orders of magnitude after photoinduced electron transfer (a record for photoswitchable organic semiconductors) and generation of radical cation⋅⋅⋅π interactions, and fell by approximately 81 % at 100 °C through reverse electron transfer and degeneration of the radical cation⋅⋅⋅π interactions. The model semiconductor has at least two different electron transfer pathways in the decoloration process. [ABSTRACT FROM AUTHOR]

Abstract Materials that may show photochromism under X-rays have higher spatial resolution for visual low-energy X-rays detection over the commercial instruments and greater X-ray sensitivity than silver salt-based radiographic films. In this work, we discovered that the known MOF, [Zn(OOCH) 2 (Bpy)] n (Bpy = 4,4′-bipyridine), showed rare photochromic behaviour upon irradiation of hard and soft X-rays at room temperature. Graphical abstract Rare X-ray-induced photochromism at room temperature, with potential application for X-ray detection, was observed for a known MOF. Image 1 Highlights • Rare X-ray-induced photochromism at room temperature was observed for a known MOF built by non-photochromic ligands. • The mechanism of the X-ray-induced photochromic has been studied. • The MOF shows a potential application on X-ray detection. [ABSTRACT FROM AUTHOR]

Despite the great prospects of alkali metal batteries, safety concerns associated with dendrite growth still limit their commercial applications. An attractive alternative is to use the room temperature liquid sodium–potassium alloy as the anode, which inherently prevents dendrite growth. Currently, Na–K alloy anodes allow only Na+ or K+ to be cycled, depending on the choice of electrolyte and ion selectivity of the cathode, which results in reduced energy density of the battery. Herein, the possibility of concurrent use of both Na+ and K+ ions in Na–K alloy anodes is explored, and the working mechanism by operando optical microscopy is investigated. It is found that the type of deposited metal is dictated by both salt and solvent in electrolyte. Impressively, Na–K co‐deposition is observed in KFSI‐DME electrolyte for the first time, which strongly influences the dendrite morphology and evolution. Furthermore, the current density also has a great impact on the deposition pattern, which allows dendrite‐free Na/K deposition on the liquid‐alloy anode. These findings enrich our understanding of the intricate electrochemical behaviors of Na–K binary electroactive alloy systems and offer guidance for the sufficient use of Na and K while avoiding dendrite formation in such liquid‐alloy batteries. [ABSTRACT FROM AUTHOR]

Construction of heterojunctions to photocatalysts is one of the most promising approaches to improve charge separation efficiency; however, the established constructing processes usually require high‐temperature conditions and/or the adding of highly concentrated or expensive exotic species, and the improvement of effective contact and charge exchange between heterojunction components remains a problem. This work proposes an unprecedented "photobreeding" method and realizes the direct growth of Zn nanowires and Mott–Schottky heterojunctions from ZnS or viologen‐coated ZnS microspheres through a photochemical reaction at room temperature without external species, while demonstrating the hypothesis proposed 140 years ago on the formation of Zn in the photochromic process of ZnS. After photobreeding of the heterojunctions, the hydrogen production efficiency of the photocatalysts increases by 2 orders of magnitude. This inexpensive, facile and efficient synthetic method will find applications in H2 production, organic synthesis, CO2 reduction, nitrogen fixation, and so on. [ABSTRACT FROM AUTHOR]

Single‐component semiconductors with photoresponse to full solar spectrum are highly desirable to simplify the device structure of commercial photodetectors and to improve solar conversion or photocatalytic efficiency but remain scarce. This work reports bottom‐up photosynthesis of an air‐stable radical semiconductor using BiI3 and a photochromism‐active benzidine derivative as a photosensitive functional motif. This semiconductor shows photoconductivity to full solar spectrum contributed by radical and non‐radical forms of the benzidine derivative. It has also the potential to detect X‐rays because of strong X‐ray absorption coefficient. This finding opens up a new synthetic method for radical semiconductors and may find applications on extending photoresponsive ranges of perovskites, transition metal sulfides, and other materials. [ABSTRACT FROM AUTHOR]

Many caregivers of individuals who are frail and elderly face financial hardships that have negative consequences that compound over time. This article explores the causes of these hardships, reviews Medicaid home and community-based interventions, and related government financial supports that have been used to alleviate them and concludes with recommendations for social work practice and social policy. [ABSTRACT FROM AUTHOR]

N‐doped carbons, as promising anode materials for energy storage, are generally modified by the additional heteroatoms (B, P, and S) doping to further promote the electrochemical performance. However, the promotion mechanism by such additional doping, especially its interplay with N‐containing species, remains unclear. Herein, by adopting N/S co‐doped carbon as a model system, it is found that S‐doping can significantly improve the content of pyridinic‐N, i.e., the most energetically favorable N type for K+ storage. Theoretical calculations reveal that such S‐induced pyridinic‐N improvement possibly originates from its catalytic effect that can facilitate the transition from edge quaternary‐N to pyridinic‐N. The resultant high content of pyridinic‐N, together with the additional S species, ensures abundant active sites for K+ storage. Accordingly, the N/S co‐doped carbon anode delivers both a high reversible capacity (422.9 mA h g−1 at 0.05 A g−1) and an impressive cyclic stability (249.6 mA h g−1 at 1 A g−1 over 4000 cycles). Moreover, in/ex situ characterizations further verify the merits of N/S co‐doped carbon from the perspective of compositional evolution and structural stability. This study unravels the origin of enhanced K+ storage by N/S co‐doping, which also helps to understand the synergistic effects of other heteroatoms co‐doping systems. [ABSTRACT FROM AUTHOR]

The (electro)chemical reactions between Li1.3Al0.3Ti1.7(PO4)3 (LATP) solid‐state electrolyte and lithium metal plague the practical applications of LATP. A commonly used strategy to tackle this issue is to construct an ionic conductor layer to stabilize Li/LATP interface. Herein, it is demonstrated that an electronic conductor interlayer (Al or Ag) can also greatly enhance the interfacial stability of Li/LATP. To unveil the origin of the enhanced interfacial stability, a series of techniques, including in situ electron and optical microscopies, kelvin probe force microscopy, and finite element analysis, is exploited. Control experiments show clearly that Al layer can effectively homogenize the electric field distribution, which enables the uniform growth of interphases and thus prevents stress concentration and crack propagation. Moreover, when coupled with solid polymer electrolyte (SPE) to form Al‐SPE bilayer, it can effectively protect LATP from electron attack and interphase formation. Remarkably, Li symmetrical cells with an Al‐SPE bilayer exhibit superior stability of more than 5000 h at 0.2 mA cm−2, among the best cycling performances to date. This work presents an in‐depth understanding of the mechanism of the enhanced interfacial stability enabled by electronic conductor interlayers, as well as a universal interface architecture to boost the cyclability of solid‐state batteries. [ABSTRACT FROM AUTHOR]

This study investigates the possible causes for the precipitation of Guangdong during dragon-boat rain period (DBRP) in 2022 that is remarkably more than the climate state and reviews the successes and failures of the prediction in 2022. Features of atmospheric circulation and sea surface temperature (SST) are analyzed based on several observational datasets for nearly 60 years from meteorological stations and the NCEP/NCAR Global Reanalysis Data. Results show that fluctuation of the 200-hPa westerly wind as well as the westerly jet is strengthened due to the propagation of wave energy, leading to strong updraft over southern China. Activities of a subtropical high and a shear line provide favorable conditions for the transport of moisture to Guangdong. With the support of powerful southwest winds, extreme precipitation is induced. ENSO is a good indicator of atmospheric circulation at mid-and high-levels during the DBRP in 2022 but it performs badly at low levels. During recent years, the influence of ENSO on precipitation during the DBRP has decreased obviously. The SSTA of tropical southeast Atlantic (SEA) in spring may become the key indicator. During the years with warm SEA, wave trains propagate from northwest to southeast over Eurasia with energy enhancing the westerly jet, conducive to updraft over southern China and the occurrence of heavy precipitation. Meanwhile, the Rossby wave is triggered over Maritime Continent by heat sources of southern Atlantic-western Indian Ocean through the Gill response. Thus, strong transport of moisture and heavy rainfall occur. [ABSTRACT FROM AUTHOR]

The development of high-performance tea aroma sensors has great significance for evaluating tea quality and monitoring tea plant pests and diseases. Hence, we fabricate a tea aroma sensor based on tungsten oxide with abundant oxygen vacancies for the rapid response of tea aroma in ppb-level. The tea aroma sensor exhibits a high sensitivity with a value of about 25 and the corresponding response and recovery time are 19 s and 5 s at 275 ℃ for 5 ppm linalool, respectively. It also shows impressive low detection limit with a response value of 2.5 for 150 ppb linalool at 275 ℃. In addition, the WO 3-x based tea aroma sensor also shows excellent selectivity, cyclic and long-term stability. The outstanding sensing performance of WO 3-x based tea aroma sensor for linalool is mainly attributed to the abundant oxygen vacancies. Theoretical calculations further demonstrate that the oxygen vacancies contribute to adsorb linalool molecules and enhance electronic interaction between linalool molecules and WO 3-x , resulting in a remarkable sensing performance for linalool. Furthermore, a portable wireless prototype based on the tea aroma sensor is developed to achieve the real-time online remote monitoring of linalool. This work paves the way for designing high-performance tea aroma sensor and provides the methods for applying tea aroma sensor to assess tea quality and monitor infestation of tea plant pests and diseases. [Display omitted] • The 3D urchin-like WO 3-x with abundant oxygen vacancies provides more adsorption sites for linalool sensing response. • WO 3-x based sensor is used for the detection of tea aroma with a concentration as low as 150 ppb at 275 ℃. • DFT calculations are applied to reveal the enhanced sensing mechanism of oxygen vacancies for linalool sensing. • A lab-made real-time online remote monitoring system for the detection of tea aroma. [ABSTRACT FROM AUTHOR]

Engineering heterogeneous composite electrodes consisting of multiple active components for meeting various electrochemical and structural demands have proven indispensable for significantly boosting the performance of lithium‐ion batteries (LIBs). Here, a novel design of ZnS/Sn heterostructures with rich phase boundaries concurrently encapsulated into hierarchical interconnected porous nitrogen‐doped carbon frameworks (ZnS/Sn@NPC) working as superior anode for LIBs, is showcased. These ZnS/Sn@NPC heterostructures with abundant heterointerfaces, a unique interconnected porous architecture, as well as a highly conductive N‐doped C matrix can provide plentiful Li+‐storage active sites, facilitate charge transfer, and reinforce the structural stability. Accordingly, the as‐fabricated ZnS/Sn@NPC anode for LIBs has achieved a high reversible capacity (769 mAh g−1, 150 cycles at 0.1 A g−1), high‐rate capability and long cycling stability (600 cycles, 645.3 mAh g−1 at 1 A g−1, 92.3% capacity retention). By integrating in situ/ex situ microscopic and spectroscopic characterizations with theoretical simulations, a multiscale and in‐depth fundamental understanding of underlying reaction mechanisms and origins of enhanced performance of ZnS/Sn@NPC is explicitly elucidated. Furthermore, a full cell assembled with prelithiated ZnS/Sn@NPC anode and LiFePO4 cathode displays superior rate and cycling performance. This work highlights the significance of chemical heterointerface engineering in rationally designing high‐performance electrodes for LIBs. [ABSTRACT FROM AUTHOR]

The first NLO-photoswitchable crystalline material with a chiral ligand, which is also the first photochromic metalloviologen compound with NLO-photoswitchable properties, was found. [Display omitted] • This article reports the first NLO-photoswitchable crystalline material with a chiral ligand. • This work indicates that the direct use of a chiral unit as a ligand is a controllable approach to design and synthesize NLO-photoswitchable crystalline materials. • The title compound is the first photochromic metalloviologen compound with NLO-photoswitchable properties. Photochromic nonlinear optical (NLO) crystals may realize photoswitching of second harmonic generation (SHG) effect without the assistance of external stimuli or special supported media that other materials usually need. However, they were generally synthesized through chirality spontaneous separation or adopting a chiral species as a media, and thus the synthesis was not easy to control. In this article, we report the first NLO-photoswitchable crystalline material with a chiral ligand, which is also the first photochromic metalloviologen compound with NLO-photoswitchable properties. Our finding indicates that the direct use of a chiral unit as a ligand is a controllable approach to synthesize NLO-photoswitchable crystalline materials. [ABSTRACT FROM AUTHOR]

As promising conversion‐type anode materials for potassium‐ion storage, transition metal chalcogenides (TMCs) exhibit high energy density but suffer severe capacity fading, which is generally ascribed to their large volume expansion and the associated structural degradation. Instead, this study emphasizes that the aggregation of nanosized TMCs during conversion reaction is a more crucial reason for the following serious electrode failures. This issue has not received enough attention, and especially the detailed aggregation mechanism and its relationship to electrode failures remains unclear. Thus, by combining in situ and ex‐situ electron microscopies, the aggregation evolution of nanosized CoS2 is systematically investigated from micro to macro scale. The aggregation originates from the coalescence of the K2S matrix during potassiation, which constantly develops into larger‐scale agglomerates as the cycling continues, eventually leading to electrode fragmentation, etc. To address this issue, an anti‐aggregation strategy is proposed through isolating CoS2 nanoparticles inside individual carbon nanoshells. Impressively, the CoS2 aggregation is strictly confined within each nanoshell, which prevents their extensive aggregation across the electrode, resulting in the superior structural and electrochemical stability. This work reveals the mechanism of aggregation‐induced electrode failures and proposes the necessity of anti‐aggregation of nanosized active materials for the design of high‐capacity electrodes. [ABSTRACT FROM AUTHOR]

[Display omitted] Nickel-rich (Ni-rich) cathode materials, LiNi x Co y Mn z O 2 (NCM, x ≥ 0.9, x + y + z = 1) hold great promise for developing high energy density lithium ion batteries especially for vehicle electrification. However, the practical application of Ni-rich cathode materials is still suffered from fast structural and interfacial degradation, and the resulted capacity decay. In this study, a diazacyclo type electrolyte additive, 2-fluoropyrazine (2-FP), was explored for the first time to boost the interfacial stabilization of single crystal LiNi 0.90 Co 0.05 Mn 0.05 O 2 (NCM90) cathode. The capacity retention of the NCM90 is evidently promoted from 72.3% to 82.1% after 200 cycles at 1C (180 mA g−1) when adding 0.2% 2-FP into the electrolyte. The improvement of the electrochemical performance is ascribed to the generation of a compact and homogeneous cathode electrolyte interphase (CEI) film through ring-opening electrochemical polymerization of 2-FP upon the NCM90 electrode particles. This enhanced CEI layer benefits the suppression of the decomposition of LiPF 6 electrolyte and the dissolution of the transition metals (Co and Mn), thus preventing the detrimental side reactions between the NCM90 electrode and the electrolyte. [ABSTRACT FROM AUTHOR]

This study delves into the complex dynamics of energy transfer and release during the fracture of unidirectional (UD) fiber-reinforced thermoplastic composites. Conducted through meticulous experimental observations and rigorous energy analysis, the research presents groundbreaking conclusions on the fracture toughness and energy conversion efficiency of UD carbon fiber composites under various loading conditions. A prominent focus is on how these mechanical properties are intricately linked to the sample's fiber orientation angles and the external conditions applied during testing. The work employed tapered double cantilever beam (TDCB) as the far-field boundary to investigate the energy changes, transfer, and conversion processes during the crack propagation of unidirectional fiber reinforced thermoplastics (UDFRTPs) structures. It was found that throughout the entire propagation process, blunt extension occurs first followed by inertial extension. This is because in the initial stage of crack propagation, the stored elastic energy in the structure is relatively small, making the crack tip prone to blunting. This continuous blunting impedes the release of internal strain energy in the structure, with blunt extension accounting for a very small proportion of the entire fracture process. When the internal strain energy in the structure continues to increase to a certain extent, the blunting of the crack tip cannot prevent the release of a large amount of elastic energy inside the structure. At the same time, the excess released strain energy converts into kinetic energy and continually impacts the blunted region at the crack tip. At this point, the propagation transitions into the inertial extension stage, which occupies a significant portion of the entire fracture process. [ABSTRACT FROM AUTHOR]

[Display omitted] Developing suitable electrode materials capable of tolerating severe structural deformation and overcoming sluggish reaction kinetics resulting from the large radius of potassium ion (K+) insertion is critical for practical applications of potassium-ion batteries (PIBs). Herein, a superior anode material featuring an intriguing hierarchical structure where assembled MoSSe nanosheets are tightly anchored on a highly porous micron-sized carbon sphere and encapsulated within a thin carbon layer (denoted as Cs@MoSSe@C) is reported, which can significantly boost the performance of PIBs. The assembled MoSSe nanosheets with expanded interlayer spacing and rich anion vacancy can facilitate the intercalation/deintercalation of K+ and guarantee abundant active sites together with a low K+ diffusion barrier. Meanwhile, the thin carbon protective layer and the highly porous carbon sphere matrix can alleviate the volume expansion and enhance the charge transport within the composite. Under these merits, the as-prepared Cs@MoSSe@C anode exhibits a high reversible capacity (431.8 mAh g−1 at 0.05 A g−1), good rate capability (161 mAh g−1 at 5 A g−1), and superior cyclic performance (70.5% capacity retention after 600 cycles at 1 A g−1), outperforming most existing Mo-based S/Se anodes. The underlying mechanisms and origins of superior performance are elucidated by a set of correlated in-situ/ex-situ characterizations and theoretical calculations. Further, a PIB full cell based on Cs@MoSSe@C anode also exhibits an impressive electrochemical performance. This work provides some insights into developing high-performance PIBs anodes with transition-metal chalcogenides. [ABSTRACT FROM AUTHOR]

Tropical cyclone (TC) annual frequency forecasting is significant for disaster prevention and mitigation in Guangdong Province. Based on the NCEP-NCAR reanalysis and NOAA Extended Reconstructed global sea surface temperature (SST) V5 data in winter, the TC frequency climatic features and prediction models have been studied. During 1951-2019, 353 TCs directly affected Guangdong with an annual average of about 5.1. TCs have experienced an abrupt change from abundance to deficiency in the mid to late 1980 with a slightly decreasing trend and a normal distribution. 338 primary precursors are obtained from statistically significant correlation regions of SST, sea level pressure, 1000hPa air temperature, 850hPa specific humidity, 500hPa geopotential height and zonal wind shear in winter. Then those 338 primary factors are reduced into 19 independent predictors by principal component analysis (PCA). Furthermore, the Multiple Linear Regression (MLR), the Gaussian Process Regression (GPR) and the Long Short-term Memory Networks and Fully Connected Layers (LSTM-FC) models are constructed relying on the above 19 factors. For three different kinds of test sets from 2010 to 2019, 2011 to 2019 and 2010 to 2019, the root mean square errors (RMSEs) of MLR, GPR and LSTM-FC between prediction and observations fluctuate within the range of 1.05-2.45, 1.00-1.93 and 0.71-0.95 as well as the average absolute errors (AAEs) 0.88-1.0, 0.75-1.36 and 0.50-0.70, respectively. As for the 2010-2019 experiment, the mean deviations of the three model outputs from the observation are 0.89, 0.78 and 0.56, together with the average evaluation scores 82.22, 84.44 and 88.89, separately. The prediction skill comparisons unveil that LSTM-FC model has a better performance than MLR and GPR. In conclusion, the deep learning model of LSTM-FC may shed light on improving the accuracy of short-term climate prediction about TC frequency. The current research can provide experience on the development of deep learning in this field and help to achieve further progress of TC disaster prevention and mitigation in Guangdong Province. [ABSTRACT FROM AUTHOR]

Abstract: A novel tetranuclear cadmium complex {Cd2[(CH3)2PPDA]2(CH3OH)Cl4}2 (1) [(CH3)2PPDA = dimethyl esterification of H2PPDA], was prepared from CdCl2·2.5H2O with (2,3-f)-pyrazino(1,10)phenanthroline-2,3-dicarboxylic acid (H2PPDA) by solvothermal reaction in methanol, and characterized by single-crystal X-ray diffraction analysis, optical diffuse reflectance and photoluminescence. In 1, cadmium ions are bridged by Cl− ions into a tetranuclear oligomeric chain further connected into a 3D supramolecular network by intermolecular CCl, OCl, and CO hydrogen bonds. Compound 1 displays fluorescence with a lifetime value of ~5.88ns in the visible region under visible-light excitation, and the origin of the luminescent emission is primary assigned to the combination of intraligand π–π* transition of (CH3)2PPDA ligand and ligand to ligand charge transfer from Cl− to (CH3)2PPDA which is probed by the density of state (DOS) calculations. [Copyright &y& Elsevier]

Deformation and fracture mechanisms of ultrathin Si nanowires (NWs), with diameters of down to ∼9 nm, under uniaxial tension and bending were investigated by using in situ transmission electron microscopy and molecular dynamics simulations. It was revealed that the mechanical behavior of Si NWs had been closely related to the wire diameter, loading conditions, and stress states. Under tension, Si NWs deformed elastically until abrupt brittle fracture. The tensile strength showed a clear size dependence, and the greatest strength was up to 11.3 GPa. In contrast, under bending, the Si NWs demonstrated considerable plasticity. Under a bending strain of <14%, they could repeatedly be bent without cracking along with a crystalline-to-amorphous phase transition. Under a larger strain of >20%, the cracks nucleated on the tensed side and propagated from the wire surface, whereas on the compressed side a plastic deformation took place because of dislocation activities and an amorphous transition. [ABSTRACT FROM AUTHOR]

Abstract: A novel 3-D inorganic open-framework containing unusual heptanuclear quasi-supertetrahedra, Cd7I12S·3H2O (1), was obtained by hydrothermal reaction and structurally characterized. Optical absorption spectrum reveals that the presence of an optical gap of 2.26eV, indicating that compound 1 is a semiconductor. [Copyright &y& Elsevier]

To study compositional trends associated with open and closed system metamorphism and/or shock-induced heating of the L4-6 chondrite parent(s), we used ICPMS and RNAA to quantify 51 trace elements in 48 chemically representative fall samples. With these data, we used graphic and two multivariate statistical methods for examining evidence for compositional differences with respect to petrographic type and degree of shock loading. Comparisons of mildly shocked (S1-S3) L5 and L6 suites (9 and 8 chondrites, respectively) yield no convincing statistical evidence for a difference in trace element content. Our multivariate comparisons show a difference on a model-dependent basis, but yield indeterminate results on a model-independent basis. Compositionally, suites of strongly shocked (S4-S6) and mildly shocked L4-6 chondrites (26 and 19 samples, respectively) can be distinguished at statistically significant levels on both model-dependent and -independent bases. In the strongly shocked suite, contents of refractory lithophiles are higher, and siderophiles and volatiles are lower than those of the mildly shocked suite at moderately (p ≤ 0.05) to highly significant (p ≤ 0.01) levels. Our studies suggest that chemical differences from vaporization and loss of volatiles along with metal/silicate partitioning are present from extended cooling of shock-heated bodies produced by intermittent impacts, especially the massive impact(s) that disrupted the L chondrite parent(s) ∼500 Ma ago. [Copyright &y& Elsevier]

The nucleation and growth of Li metal during deposition and the associated dendrite penetration are the critical and fundamental issues influencing the safety and power density of solid‐state lithium metal batteries (SSLBs). However, investigations on Li metal deposition/dissolution especially the formation and growth of Li dendrites and their determining factors in the all‐solid‐state electrochemical systems are still lacking. In this work, in situ observations of the Li metal growth process, and defects induced heterogeneous deposition under cathodic load, are reported. By exploiting in situ scanning electron microscopy, along with electrochemical analytical approaches, the spatial distribution and morphological evolution of the deposited Li at the electrode|solid electrolyte interface are obtained and discussed. This investigation reveals that the formation of lithium whiskers is decided by the local Li ion flux and the deposition active sites, which are closely dependent on the content and types of defects in the polycrystalline electrolyte. Moreover, the defect regions exhibit faster Li deposition kinetics and higher nucleation tendency. These results can advance the fundamental understanding of the Li penetration mechanism in SSLBs. [ABSTRACT FROM AUTHOR]

Similarities in sizes, shapes, and physical properties between carbon dioxide (CO2) and acetylene (C2H2) make it a great challenge to separate the major impurity CO2 from products in C2H2 production. The use of porous materials is an appealing path to replace current very costly and energy‐consuming technologies, such as solvent extraction and cryogenic distillation; however, high CO2/C2H2 uptake ratio with minor adsorption of C2H2 at standard pressure was only unexpectedly observed in scarce examples in recent years although the related research started early at 1950s, and general design strategies to realize this aim are still absent. This work has successfully developed an efficient PIET strategy and obtained the second highest CO2/C2H2 adsorption ratio for porous materials in a proof‐of‐concept MOF with a photochromism‐active bipyridinium zwitterion. An unprecedented photocontrollable gate effect, owing to change of interannular dihedral after photoinduced generation of radical species, was also observed for the first time. These findings will inspire design and synthesis of porous materials for high efficient gas adsorption and separation. [ABSTRACT FROM AUTHOR]

A new design strategy through the synergy of Mo(VI)–Mo(V) intervalence charge transfer and π(radical)–π(radical/cation) interactions is proposed to obtain semiconductors with photoresponsive ranges covering the whole UV–SWIR (ultraviolet–shortwave near-infrared; ca. 250–3000 nm) region. With this strategy, a viologen-based molybdate semiconductor with a UV–SWIR photoresponsive range was obtained through UV/X-ray irradiation or thermal annealing. The thermally annealed semiconductor has the highest conversion and the best photocurrent response in the range of 355–2400 nm. [ABSTRACT FROM AUTHOR]

Metallic bismuth has drawn attention as a promising alloying anode for advanced potassium ion batteries (PIBs). However, serious volume expansion/electrode pulverization and sluggish kinetics always lead to its inferior cycling and rate properties for practical applications. Therefore, advanced Bi‐based anodes via structural/compositional optimization and sur‐/interface design are needed. Herein, we develop a bottom‐up avenue to fabricate nanoscale Bi encapsulated in a 3D N‐doped carbon nanocages (Bi@N‐CNCs) framework with a void space by using a novel Bi‐based metal‐organic framework as the precursor. With elaborate regulation in annealing temperatures, the optimized Bi@N‐CNCs electrode exhibits large reversible capacities and long‐duration cyclic stability at high rates when evaluated as competitive anodes for PIBs. Insights into the intrinsic K+‐storage processes of the Bi@N‐CNCs anode are put forward from comprehensive in situ characterizations. [ABSTRACT FROM AUTHOR]

Two new crystalline inorganic-organic hybrid compounds, namely, {[Zn(PCV) 0.5 (BDC) 0.5 ]·3H 2 O} n (1) and {[Cd(PCV) 0.5 (BDC) 0.5 (H 2 O)]·3H 2 O} n (2) have been solvothermally synthesized from the 1,4-benzenedicarboxylate (BDC2−) ligand and the viologen analog 1-(4-carboxyphenyl)-4,4′-bipyridinium (PCV). In these two compounds, PCV ligands coordinate with metal atoms to form 1D zigzag chains, and the chains are further bridged by the BDC2− ligands to yield a wave-like layer with a (4, 4) net topology. For 1 , three layers interpenetrate with each other to construct a triple-layer structure, which are stacked along the b direction through van der Waals's force to yield the final 3D structure where the channels along the a direction host the lattice water molecules. In comparison, two layers interpenetrate with each other to construct a double-layer structure, which further interpenetrate to form the final 3D structures where the lattice water molecules locate in channels along a direction. Both compounds showed photochromism accompanied with dramatic decrease of photoluminescence upon irradiation. The powdered sample of 1 can deposit easily on paper by diffusing into ethanol solution, which displays the potential application as an inkless and erasable print medium. We synthesized two new photochromic inorganic-organic hybrid materials which showed the same wave-like layer with a (4, 4) topology. Both compounds showed photochromic phenomenon. However, owing to the different π ... π interactions and densely packing, two compounds exhibit different photochromic properties. Importantly, compound 1 can be used as inkless and erasable printing media. Image 1 • Two novel viologen-based CPs are prepared via the efficient method. • Both compounds showed photochromic phenomena. • Compound 1 can be used as an inkless and erasable print medium. [ABSTRACT FROM AUTHOR]

Potassium‐ion batteries (PIBs) are promising alternatives to lithium‐ion batteries because of the advantage of abundant, low‐cost potassium resources. However, PIBs are facing a pivotal challenge to develop suitable electrode materials for efficient insertion/extraction of large‐radius potassium ions (K+). Here, a viable anode material composed of uniform, hollow porous bowl‐like hard carbon dual doped with nitrogen (N) and phosphorus (P) (denoted as N/P‐HPCB) is developed for high‐performance PIBs. With prominent merits in structure, the as‐fabricated N/P‐HPCB electrode manifests extraordinary potassium storage performance in terms of high reversible capacity (458.3 mAh g−1 after 100 cycles at 0.1 A g−1), superior rate performance (213.6 mAh g−1 at 4 A g−1), and long‐term cyclability (205.2 mAh g−1 after 1000 cycles at 2 A g−1). Density‐functional theory calculations reveal the merits of N/P dual doping in favor of facilitating the adsorption/diffusion of K+ and enhancing the electronic conductivity, guaranteeing improved capacity, and rate capability. Moreover, in situ transmission electron microscopy in conjunction with ex situ microscopy and Raman spectroscopy confirms the exceptional cycling stability originating from the excellent phase reversibility and robust structure integrity of N/P‐HPCB electrode during cycling. Overall, the findings shed light on the development of high‐performance, durable carbon anodes for advanced PIBs. [ABSTRACT FROM AUTHOR]

In situ transmission electron microscopy (In situ TEM) provides a powerful approach for the fundamental investigation of structural and chemical changes during operation of all solid-state lithium batteries (ASSLBs) with high spatio-temporal resolution. In this review, we present an overview of recent progress on understanding the reaction and degradation occurring in electrodes, solid electrolytes and their interfaces and interphases during operation of ASSLBs via in situ TEM, demonstrating the general applicability of in situ TEM for elucidating the fundamental mechanisms and providing the design guidance for the development of high-performance ASSLBs. Owing to the use of solid electrolytes instead of flammable and potentially toxic organic liquid electrolytes, all solid-state lithium batteries (ASSLBs) are considered to have substantial advantages over conventional liquid electrolyte based lithium ion batteries(LIBs) in terms of safety, energy density, battery packaging, and operable temperature range. However, the electrochemistry and the operation mechanism of ASSLBs differ considerably from conventional LIBs. Consequently, the failure mechanisms of ASSLBs, which are not well understood, require particular attention. To improve the performance and realize practical applications of ASSLBs, it is crucial to unravel the dynamic evolution of electrodes, solid electrolytes, and their interfaces and interphases during cycling of ASSLBs. In situ transmission electron microscopy (TEM) provides a powerful approach for the fundamental investigation of structural and chemical changes during operation of ASSLBs with high spatio-temporal resolution. Herein, recent progress in in situ TEM studies of ASSLBs are reviewed with a specific focus on real-time observations of reaction and degradation occurring in electrodes, solid electrolytes, and their interfaces. Novel electro-chemo-mechanical coupling phenomena are revealed and mechanistic insights are highlighted. This review covers a broad range of electrode and electrolyte materials applied in ASSLBs, demonstrates the general applicability of in situ TEM for elucidating the fundamental mechanisms and providing the design guidance for the development of high-performance ASSLBs. Finally, challenges and opportunities for in situ TEM studies of ASSLBs are discussed. [ABSTRACT FROM AUTHOR]

Antimony trisulfide‐based materials have drawn growing attention as promising anode candidates for potassium‐ion batteries (PIBs) because of their high capacity and good working potential. Despite the extensive investigations on their electrochemical properties, the fundamental reaction mechanisms of Sb2S3 anodes, especially the reaction kinetics, structural changes, and phase evolutions, remain controversial or even largely unknown. Here, using in situ transmission electron microscopy, the entire potassiation–depotassiation cycles of carbon‐coated Sb2S3 single‐crystal nanowires are tracked in real time at the atomic scale. The potassiation of Sb2S3 involves multistep reactions including intercalation, conversion, and two‐step alloying, and the final products are identified as cubic K2S and hexagonal K3Sb. These findings are confirmed by density functional theory calculations. Interestingly, a rocket‐launching‐like nanoparticle growth behavior is observed during alloying reactions, which is driven by the K+ concentration gradient and release of stress. More impressively, the potassiated products (i.e., K3Sb and K2S) can transform into the original Sb2S3 phase during depotassiation, indicating a reversible phase transformation process, as distinct from other metal chalcogenide based electrodes. This work reveals the detailed potassiation/depotassiation mechanisms of Sb2S3‐based anodes and can facilitate the analysis of the mechanisms of other metal chalcogenide anodes in PIBs. [ABSTRACT FROM AUTHOR]

We report an atomic structure and property tailoring method that enables precise control of the diameter of individual double-walled carbon nanotubes (DWNTs), as well as the corresponding tuning of their tensile strength and electrical resistance. As demonstrated in a transmission electron microscope (TEM), this facile method involves the electron irradiation of DWNTs, followed by a thermal annealing process. The former process is responsible for the random atom loss and tube size reduction, whereas the latter allows for a complete structural recovery of defective nanotubes. The regarded DWNTs thus experience repeated disorder-order structural transitions, leading to the stepwise shrinkage in tube size, until the desired diameter is reached. Accordingly, these disorder-order transitions allow individual DWNTs to be controllably weakened and then strengthened, accompanied with the reversible changes in their breaking modes, as revealed by direct in-situ tensile tests. Differently, the resistance tuning of DWNTs upon irradiation/annealing does not follow the same trend, but depends significantly on the initial tube electrical characteristics and subsequent chirality transitions. These experimental results, combined with first-principles calculations, suggest that the change of tube chirality involved in the disorder-order transitions profoundly influences DWNT transport properties, but has a little impact on their mechanical strength. Image 1 [ABSTRACT FROM AUTHOR]

Metallic lithium has long been deemed as the ultimate anode material for future high‐energy‐density Li batteries. However, the commercialization of Li metal anodes remains hindered by some major hurdles including their huge volume fluctuation during cycling, unstable solid electrolyte interface (SEI), and dendritic deposition. Herein, the concept of nano‐encapsulating electrode materials is attempted to tackle these problems. Nitrogen‐doped hollow porous carbon spheres (N‐HPCSs), prepared via a facile and low‐cost method, serve as the nanocapsules. Each N‐HPCS has a lithophilic carbon shell with a thin N‐rich denser layer on its inner surface, which enables preferential nucleation of Li inside the hollow sphere. It is demonstrated by in situ electron microscopy that these N‐HPCS hosts allow Li to be encapsulated in a highly reversible and repeatable manner. Ultralong Li filling/stripping cycling inside single N‐HPCSs is achieved, up to 50 cycles for the first time. Li ion transport across multiple connected N‐HPCSs, leading to long‐range Li deposition inside their cavities, is visualized. In comparison, other types of carbon spheres with modified shell structures fail in encapsulating Li and dendrite suppression. The necessity of the specific shell design is therefore confirmed for stable Li encapsulation, which is essential for the N‐HPCS‐based anodes to achieve superior cycling performance. [ABSTRACT FROM AUTHOR]

The thin film with Si@CNTs fibrous structure is prepared based on carbon nanotube conducting networks by a sputtering process. A "face-to-face" strong contact configuration based on Si-C bonds is proven after DFT calculations, FTIR and XPS tests. The Si@CNTs film has stable electrical properties even after repeated bending at 6% engineering strain and 58.33% initial cycling volume expansion. The full cell displays 81% capacity retention after 500th cycle. This strategy redefines the conductive mode of CNTs with Si anodes. [Display omitted] • The Si@CNTs fibre film was obtained by high-vacuum magnetron sputtering. • A "face-to-face" conducting mechanism enabled by Si-C bond was proposed. • Stable electrical properties during mechanical strain and lithiation expansion. • The Si@CNTs film exhibited excellent electrical conductivity (59.74 S cm−1). • The capacity retention of the Si@CNTs electrode after 500 cycles at 6C was 81%. The three-dimensional conductive network has been developed, creating a continuous pathway for Si anodes. Nonetheless, the weak physical contact between Si particles and the conducting network is prone to separation due to expansion stress and the solid electrolyte interface. This results in a rapid decline in cell cycling performance. Herein, we have developed a binder free Si@CNTs fibrous thin film structure using carbon nanotube (CNT) conducting networks through a high vacuum magnetic sputtering process of molecular reorganization. With Fourier Transform Infrared (FTIR), X-ray Photoelectron Spectroscopy (XPS) tests and density functional theory (DFT) calculations, we propose a strong "face-to-face" contact configuration based on Si-C bonds. The Si@CNTs film demonstrated stable mechanical and electrical properties even after repeated bending and stretching of up to 6%. In-situ transmission electron microscopy confirmed that the initial cycling volume expansion of the Si@CNTs fibers with Si-C bonds was only 58.33%. Furthermore, the full cell using Si@CNTs anode enabled stable high-rate cycling performance at 6C after 500 cycles. This innovative strategy redefines the conductive mode of CNTs with Si anodes. [ABSTRACT FROM AUTHOR]

2,4,6‐Tri(4‐pyridyl)‐1,3,5‐triazine (tpt) is a widely used ligand for functional coordination compounds. In this work, tpt has shown unprecedented photochromism in the crystalline state. Experimental and theoretical data has revealed that the photocoloration of tpt very likely originates from intramolecular charge separation and the formation of a triplet diradical product. This finding demonstrates a new simple, neutral photochromic molecule and endows the tpt molecule and related compounds with potential optical applications. [ABSTRACT FROM AUTHOR]

• Construction rules of iodoargentate(I) and iodocuprate(I) hybrids is described. • Directed synthesis of iodoargentates(I) and iodocuprates(I) are highlighted. • Photo- and thermo-chromism of iodoargentates(I)/iodocuprates(I) are described. d10 iodoargentates(I)/iodocuprates(I) are a family of organic-inorganic hybrids with diverse structural topologies and fascinating photoelectric properties. Growing interest in this field has focused on realizing controllable dimensional extension of the inorganic moieties and assembling functional materials based on the electron-rich features of iodoargentates(I)/iodocuprates(I). This feature article reviews the recent progress of d10 iodoargentate(I)/iodocuprate(I) hybrids from structural construction and directed synthesis rules to their photochromic and thermochromic properties. [ABSTRACT FROM AUTHOR]

• Fe 3 O 4 , (α + γ)-Fe 2 O 3 and α-Fe 2 O 3 were firstly used for Cd immobilization in sediment. • (α + γ)-Fe 2 O 3 possessed the best efficiency in Cd immobilization. • Three synthesized iron oxides effectively reduce mobile fraction of Cd in sediment. • The immobilization mechanism of three synthesized iron oxides on Cd were studied. In situ immobilization remediation has attracted attention due to its effectiveness in treating contaminated sediment. In this study, the effects of three iron oxides with different crystallinities Fe 3 O 4 , (α + γ)-Fe 2 O 3 , and α-Fe 2 O 3 were investigated as potential in situ amendments for Cd remediation in sediment. The three amendments were mixed with the sediment at dosages of 0%, 2%, and 6% (w/w) for 1–56 d of treatment. The changes of the oxidation-reduction potential (Eh) and pH in the treated sediment samples indicated the related mechanism for Cd immobilization. The experimental results showed that when the sediment sample was treated with synthesized iron oxides for 56 d, the TCLP (toxicity characteristic leaching procedure) leachable Cd in the sediment decreased by 29.43–57.26%, and the PBET (physiologically-based extraction test) extracted Cd decreased by 17.22–39.40%. Additionally, (α + γ)-Fe 2 O 3 exhibited better performances than the other iron oxides. The BCR (Community Bureau of Reference) extraction, results suggested that synthetized iron oxides can effectively reduce the mobile fraction and increase the stable fraction of Cd, which in turn reduces the bioavailability of Cd in the sediment. The analysis of the Fe dissolution risk showed that a high dosage Fe 3 O 4 treatment posed a potential threat to the organisms and suggested that the secondary Fe minerals were involved in the Cd immobilization. Overall, this study provides new insight into the potential applications of iron oxides for Cd immobilization in sediment. [ABSTRACT FROM AUTHOR]

Superlattice materials offer new opportunities to modify optical and electrical properties of recently emerging 2D materials. The insertion of tetraethylbenzidine (EtDAB) into interlamination of the established 2D PbI2 semiconductor through a mild solution method yielded the first lead iodide superlattice, EtDAB⋅4PbI2 (EtDAB=tetraethylbenzidine), with radical and non‐radical forms. The non‐radical form has a non‐ionic structure that differs from the common ionic structures for inorganic–organic hybrid lead halides. The radical form shows five orders of magnitude greater conductance and broader photoconductive response range (UV/Vis → UV/Vis‐IR), than pure PbI2 and the non‐radical form of the superlattice. [ABSTRACT FROM AUTHOR]

A new metal–organic framework with excellent water stability, {H[(N(CH3)4)2][Gd3(NIPA)6]}·3H2O (1, H2NIPA = 5-nitroisophthalic acid), displays a proton conductivity of 7.17 × 10−2 S cm−1 (at 75 °C and 98% relative humidity), which is among the highest values for proton-conducting MOFs. [ABSTRACT FROM AUTHOR]

Introduction of the viologen cation, a well-known electron acceptor, into molybdate layers led to a dramatic change in the conductance of the 2D hybrid material in the process of photo-induced or thermo-induced coloration, which provides an alternative approach to manipulate the electronic properties of 2D semiconductors via external optical/thermal stimuli. [ABSTRACT FROM AUTHOR]

A novel nitrogen-doped carbon nanosphere with lithiophilic ZnO nanoparticles encapsulated by interconnected pomegranate-like carbon sheets is designed and fabricated, and the lithium deposition behavior in it is systematically investigated via in-situ transmission electron microscopy. The well-designed pomegranate-like carbon sheets within the carbon nanosphere can prevent lithiophilic seeds from detaching or aggregating during cycling, and meanwhile offer individual void to accommodate deposited Li. Such a dual-confinement effect enables dendrite-free Li deposition and long cycling life. [Display omitted] • A novel pomegranate-like carbon nanosphere with lithiophilicity is constructed. • The well-designed carbon networks provide dual-confinement for Li encapsulation. • The ZnO@NPCS electrode delivers long cycling life with high average CEs. • In-situ TEM and phase-field simulations confirm the dual-confinement mechanism. • The dual-confinement strategy can be extended to other alkalis anodes. The uncontrollable dendrite growth and infinite volume expansion of Li during cycling lead to low Coulombic efficiency (CE) and short cycling life, severely impeding the commercial progress of lithium metal batteries (LMBs). In this work, nitrogen-doped carbon nanospheres (CSs) with ultrafine lithiophilic ZnO nanoparticles encapsulated by interconnected pomegranate-like carbon sheets (denoted as ZnO@NPCS) have been designed and constructed to serve as novel lithium hosts. The ultrafine ZnO nanoparticles uniformly distributed in the CSs can significantly reduce the Li nucleation barrier, while the well-designed pomegranate-like carbon sheets within the CSs can provide continuous and fast electron/ion transport channels, accelerating the Li+ transfer kinetics. Moreover, the internal interconnected carbon networks can confine the lithiophilic nanoparticles, preventing them from detaching or aggregating during cycling, and meanwhile offer individual voids to accommodate deposited Li. Thus, both lithiophilic seeds and deposited Li can be well confined in the pomegranate-like structure. Such a dual-confinement effect enables the ZnO@NPCS electrode to exhibit ultralong cycling life for more than 1000 cycles with ultrahigh CE (>99.5 %) without Li dendrites growth, which is further validated by in-situ transmission electron microscopy and phase-field simulations. Therefore, this dual-confinement strategy provides an inspiring insight to design superior Li hosts for developing superior LMBs and can be extended to other battery systems. [ABSTRACT FROM AUTHOR]

• A Co-free, Ni-rich cathode (NA96) is proposed and optimized by Mo or W doping. • Doped-NA96 cathodes show enhanced electrochemical performances in comparison to NA96. • W-NA96 has superior rate capability and 89% capacity retention (300 cycles, 1C). • The H2 → H3 phase transitions and surface degradation are suppressed in W- and Mo-NA96. Ni-rich layered oxides, such as LiNi x Co y Mn 1−x−y O 2 /LiNi x Co y Al 1−x−y O 2 , are promising cathode materials for lithium-ion batteries due to their high capacity. However, the commercial applicability of these materials is hindered by their inferior cyclic stability and limited cobalt supply. Herein, a cost-effective Al-substituted, Co-free, Ni-rich cathode (LiNi 0.96 Al 0.04 O 2 , NA96) is proposed and optimized by doping with high-valence molybdenum or tungsten. It is demonstrated that the introduction of Mo or W refines of primary particles and creates more compact microstructures. Moreover, Mo/W doping effectively mitigates deleterious H2→H3 phase transitions, formation of cracks, and surface lattice oxygen loss, as confirmed through ex/in situ characterizations and density functional theory calculations. As a result, both Mo-NA96 and W-NA96 exhibit superior structural integrity, long-term cyclability, rate capability, and thermal stability compared to the undoped counterparts. Notably, W-NA96 displays exceptional rate capability, achieving a discharge capacity of 185.9 mAh g−1 at a high current rate of 10C, even without Co. Furthermore, the 2 Ah pouch-type full cells using W-NA96 paired with graphite exhibit excellent capacity retention (89% after 300 cycles at 1C). These findings highlight the potential of combining Al and high-valence elements in Co-free, Ni-rich cathodes, offering a new perspective for designing high-performance cathodes. [ABSTRACT FROM AUTHOR]

A radiochromic material with energy-dependent X-ray-induced photochromism was obtained by incorporating a radiosensitive glycolate ligand into an electron-transfer photochromic metalloviologen system. It is highly promising for detecting soft X-rays with energies less than 2 keV and may find application in qualitatively and visually distinguishing the energy range of X-rays. [ABSTRACT FROM AUTHOR]

Viologen (N,N′-disubstituted bipyridinium) compounds are well known for their electron-transfer photochromic properties and many potential applications. However, viologen-based organic molecules, especially those with aliphatic hydrocarbon substituents, are inclined to be hygroscopic, and most of the known viologen compounds need dozens of seconds or even several minutes to exhibit photoinduced color change. The viologen–carboxylate zwitterion ligand, N,N′-dipropionate-4,4′-bipyridinium (L), is highly hygroscopic and its shortest coloration time is 5 s upon irradiation of a Xe lamp (ca. 110 mW cm−2). After coordination with ZnCl2, the obtained new compound [Zn2LCl4]n (ZnLCl) is highly stable in a wet environment (e.g. 60% relative humidity), and its shortest coloration time is 1 s upon irradiation of the same Xe lamp. X-ray diffraction analysis coupling with multiple experimental spectra (UV-vis, ESR, XPS, and IR) and density of states (DOS) calculations revealed that the photoinduced coloration of L and ZnLCl is contributed mainly by O → pyridinium and Cl → pyridinium electron transfer, respectively. The lower electronegativity of Cl over O and the shorter donor–acceptor separation may explain why ZnLCl has a shorter coloration time. Moreover, enhancement of molecular rigidity by the coordination structure may account for the improvement of moisture stability. [ABSTRACT FROM AUTHOR]

To address the issues of sluggish electronic transport and large volume variation of Fe 2 O 3 anode nanomaterials caused by repeated Li + insertion/extraction, herein we engineer an erythrocyte-like Fe 2 O 3 with thin mesoporous carbon into yolk-shell architectures, in which the erythrocyte-like Fe 2 O 3 is well confined inside the thin mesoporous carbon. In this design, the erythrocyte-like Fe 2 O 3 cores with high specific capacity together with the permeable thin carbon shells could not only greatly facilitate the fast diffusion for both ion and electron but also retain a thin and stable solid electrolyte interface (SEI) layer on its surface, resulting in excellent rate capability and cycling stability. Meanwhile, the hollow cavity between carbon shell and Fe 2 O 3 core provides extra free space for Fe 2 O 3 expansion, thus preserving the structural integrity. By virtue of their advantageous structural features, the elegant void-containing mesoporous carbon-encapsulated erythrocyte-like Fe 2 O 3 electrodes exhibit superior performance including large capacity, high rate capability and long cycle stability. More importantly, when coupled with commercial LiCoO 2 cathode, the assembled Li-ion full cell demonstrates a high reversible capacity of 615 mA h g −1 after 100 cycles at 1C with capacity retention of 83.4% as well as outstanding rate capability (675 mA h g −1 at 4C with capacity retention of 83% from 0.2C to 4C), demonstrating significant potential for future practical applications. [ABSTRACT FROM AUTHOR]