Anionic Chemistry Modulation Enabled Environmental Self-Charging Aqueous Zinc Batteries: The Case of Carbonate Ions.

Anionic chemistry modulation represents a promising avenue to enhance the electrochemical performance and unlock versatile applications in cutting-edge energy storage devices. Herein, we propose a methodology that involves anionic chemistry of carbonate anions to tailor the electrochemical oxidation-reduction reactions of bismuth (Bi) electrodes, where the conversion energy barrier for Bi (0) to Bi (III) has been significantly reduced, endowing anionic full batteries with enhanced electrochemical kinetics and chemical self-charging property. The elaborately designed batteries with an air-switch demonstrate rapid self-recharging capabilities, recovering over 80% of the electrochemical full charging capacity within a remarkably short timeframe of 1 hour and achieving a cumulative self-charging capacity of 5 Ah g-1. The aqueous self-charging battery strategy induced by carbonate anion, as proposed in this study, holds the potential for extending to various anionic systems, including seawater-based Cl- ion batteries. This work offers a universal framework for advancing next-generation multi-functional power sources.

Manipulating Atomic-Coupling in Dual-Cavity Boride Nanoreactor to Achieve Hierarchical Catalytic Engineering for Sulfur Cathode.

The catalytic process of Li2S formation is considered a key pathway to enhance the kinetics of lithium-sulfur batteries. Due to the system's complexity, the catalytic behavior is uncertain, posing significant challenges for predicting activity. Herein, we report a novel cascaded dual-cavity nanoreactor (NiCo-B) by controlling reaction kinetics, providing an opportunity for achieving hierarchical catalytic behavior. Through experimental and theoretical analysis, the multilevel structure can effectively suppress polysulfides dissolution and accelerate sulfur conversion. Furthermore, we differentiate the adsorption (B-S) and catalytic effect (Co-S) in NiCo-B, avoiding catalyst deactivation caused by excessive adsorption. As a result, the as-prepared battery displays high reversible capacity, even with sulfur loading of 13.2 mg cm-2 (E/S=4 µl mg-1), the areal capacity can reach 18.7 mAh cm-2.

Self-Powered Integrated Sensing System with In-Plane Micro-Supercapacitors for Wearable Electronics.

Self-powered integrated sensor with high-sensitivity physiological signals detection is indispensable for next-generation wearable electronic devices. Herein, a Ti3 C2 Tx /CNTs-based self-powered resistive sensor with solar cells and in-plane micro-supercapacitors (MSCs) is successfully realized on a flexible styrene-ethylene/butylene-styrene (SEBS) electrospinning film. The prepared Ti3 C2 Tx /CNTs@SEBS/CNTs nanofiber membranes exhibit high electrical conductivity and mechanical flexibility. The laser-assisted fabricated Ti3 C2 Tx /CNTs based-MSCs demonstrate a high areal energy density of 52.89 and 9.56 µWh cm-2 with a corresponding areal power density of 0.2 and 4 mW cm-2 . Additionally, the MSCs exhibit remarkable capacity retention of 90.62% after 10 000 cycles. Furthermore, the Ti3 C2 Tx /CNTs based-sensor exhibits real-time detection capability for human facial micro-expressions and pulse single under physiological conditions. The repeated bending/release tests indicate the long-time cycle stability of the Ti3 C2 Tx /CNTs based-sensor. Owing to the excellent sensing performance, the sensing array was also fabricated. It is believed that this work develops a route for designing a self-powered sensor system with flexible production, high performance, and human-friendly characteristics for wearable electronics.

A General "In Situ Etch-Adsorption-Phosphatization" Strategy for the Fabrication of Metal Phosphides/Hollow Carbon Composite for High Performance Liquid/Flexible Zn-Air Batteries.

Benefiting from the admirable energy density (1086 Wh kg-1 ), overwhelming security, and low environmental impact, rechargeable zinc-air batteries (ZABs) are deemed to be attractive candidates for lithium-ion batteries. The exploration of novel oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) bifunctional catalysts is the key to promoting the development of zinc-air batteries. Transitional metal phosphides (TMPs) especially Fe-based TMPs are deemed to be a rational type of catalyst, however, their catalytic performance still needs to be further improved. Considering Fe (heme) and Cu (copper terminal oxidases) are nature's options for ORR catalysis in many forms of life from bacteria to humans. Herein, a general "in situ etch-adsorption-phosphatization" strategy is designed for the fabrication of hollow FeP/Fe2 P/Cu3 P-N, P codoped carbon (FeP/Cu3 P-NPC) catalyst as the cathode of liquid and flexible ZABs. The liquid ZABs manifest a high peak power density of 158.5 mW cm-2 and outstanding long-term cycling performance (≈1100 cycles at 2 mA cm-2 ). Similarly, the flexible ZABs deliver superior cycling stability of 81 h at 2 mA cm-2 without bending and 26 h with different bending angles.

Connection between health risk and heavy metals in agricultural soils of China: a study based on current field investigations.

Heavy metal pollution in agricultural soil is a threat to people's health and sustainable development. However, there is currently no nationwide health risk assessment in China. In this study, we performed a preliminary assessment of heavy metals in agricultural soils of the Chinese mainland, and found obvious carcinogenic risks (total lifetime carcinogenic risk (TLCR) > 1 × 10-5). A similar spatial distribution pattern was found in soil heavy metal and the mortality of esophagus and stomach cancers. Combining the potential carcinogenic risk assessed by LCR for individual heavy metal with Pearson correlation, Geographical Detector (q statistic > 0.75 for TLCR, p < 0.05), and redundancy analysis (RDA), it was found that long-term exposure and intake route of heavy metals exceeding the maximum safety threshold (Health Canada standard) may induce digestive system (esophagus, stomach, liver, and colorectum) cancers in rural populations. Through Partial Least Squares Path Model (PLS-PM), it was also revealed that the LCR of heavy metals was closely related to the soil environmental background (path coefficients = 0.82), which in turn was affected by factors such as economic development and pollution discharge. The current research results highlight the potential carcinogenic risk to the digestive system associated with low-dose and long-term exposure to heavy metals in agricultural soils, and policymakers should propose countermeasures and solutions according to the local conditions.

Sedimentary record of silver in recent times from Chaohu Lake, East China, and its implications.

High-resolution record of silver (Ag) in lakes is indispensable for examining human impact on its deposition, and for understanding its geochemical cycling in the environment. However, such studies are extremely insufficient. In this study, a piston core (CHY) collected from the Chaohu Lake, east China, was analyzed to examine sedimentary history of Ag. A record of this metal in recent times was further reconstructed. The record displays significant changes. Prior to the 1960s, Ag concentrations stabilized at a relatively low level (0.06 ppm), but they increased rapidly (0.26 ppm) afterward. The average concentration of Ag in the profile is 0.13 ppm, higher than its crustal abundance. Enrichment factor (EF) analysis further reveals that Chaohu Lake was not polluted with Ag until the 1960s, but the pollution level increases rapidly since then, and now shows a moderate pollution. Sedimentary record of Ag closely follows population changes within the watershed, suggesting that human activity is possibly the ultimate driving factor for its distribution. Intensified industrial activities associated with population expansion may release silver to inflow rivers and Chaohu Lake, resulting in its ultimate settling down to the sediments. Sedimentary flux of Ag varies significantly between 42.9 and 392.0 µg/(m2·year), with an average of 236.8 µg/(m2·year). This is so far as we know the first high-resolution record of Ag and its flux in east China, providing new perspective for better understanding the distribution and transport of Ag in lake environment.

A "Pre-Division Metal Clusters" Strategy to Mediate Efficient Dual-Active Sites ORR Catalyst for Ultralong Rechargeable Zn-Air Battery.

To conquer the bottleneck of sluggish kinetics in cathodic oxygen reduction reaction (ORR) of metal-air batteries, catalysts with dual-active centers have stood out. Here, a "pre-division metal clusters" strategy is firstly conceived to fabricate a N,S-dual doped honeycomb-like carbon matrix inlaid with CoN4 sites and wrapped Co2 P nanoclusters as dual-active centers (Co2 P/CoN4 @NSC-500). A crystalline {CoII 2 } coordination cluster divided by periphery second organic layers is well-designed to realize delocalized dispersion before calcination. The optimal Co2 P/CoN4 @NSC-500 executes excellent 4e- ORR activity surpassing the benchmark Pt/C. Theoretical calculation results reveal that the CoN4 sites and Co2 P nanoclusters can synergistically quicken the formation of *OOH on Co sites. The rechargeable Zn-air battery (ZAB) assembled by Co2 P/CoN4 @NSC-500 delivers ultralong cycling stability over 1742 hours (3484 cycles) under 5 mA cm-2 and can light up a 2.4 V LED bulb for ≈264 hours, evidencing the promising practical application potentials in portable devices.

IncRNA KTN1-AS1 Silencing Inhibits Non-Small-Cell Lung Cancer Cell Proliferation and KTN1-AS1 Expression Predicts Survival.

Long noncoding RNA (lncRNA) KTN1 antisense RNA 1 (KTN1-AS1) has been characterized as an oncogenic lncRNA in liver cancer. In this study, we investigated the functions of KTN1-AS1 in non-small-cell lung cancer (NSCLC). A total of 66 patients (27 females and 39 males, 28 to 67 years old, mean age 47.1 ± 6.6 years) with NSCLC were enrolled in this study. KTN1-AS1 and CDK1 expression in tissue samples of NSCLC patients were analyzed using reverse transcription quantitative polymerase chain reaction (RT-qPCR). Cell cycle progression assay and cell proliferation assay were performed to analyze the role of KTN1-AS1 in cell cycle progression and cell proliferation. RT-qPCR and Western blot analyses of cells with overexpression were performed to analyze the role of KTN1-AS1 in CDK1 expression. KTN1-AS1 was upregulated in NSCLC tissues and its expression level was positive correlated with CDK1 expression. KTN1-AS1 expression was not changed with clinical stages increasing, and higher KTN1-AS1 levels were associated with poor survival of NSCLC patients. KTN1-AS1 silencing induced G1 phase cell cycle arrest of NSCLC cells and downregulated CDK1. Moreover, KTN1-AS1 silencing suppressed NSCLC cell proliferation and CDK1 overexpression attenuated the effects of KTN1-AS1 silencing on cell proliferation. KTN1-AS1 may regulate cell cycle progression in NSCLC by regulating CDK1.

Rational Design of Tungsten Selenide @ N-Doped Carbon Nanotube for High-Stable Potassium-Ion Batteries.

Potassium-ion batteries (PIBs) are deemed as one of the most promising energy storage systems due to their high energy density and low cost. However, their commercial application is far away from satisfactory because of limited suitable electrode materials. Herein, core-shell structured WSe2 @N-doped C nanotubes are rationally designed and synthesized via selenizing WO3 @ polypyrrole for the first time. The large interlayer spacing of WSe2 can facilitate the intercalation/deintercalation of K+ . Meanwhile, the core-shell structured nanotube provides favorable interior void space to accommodate the volume expansion of WSe2 during cycling. Thus, the obtained electrode exhibits superb electrochemical performance with a high capacity of 301.7 mAh g-1 at 100 mA g-1 over 120 cycles, and 122.1 mAh g-1 can remain at 500 mA g-1 even after 1300 cycles. Ex-situ X-ray diffraction analysis reveals the K-ion storage mechanism of WSe2 @N-doped C includes intercalation and conversion reaction. Density function theory (DFT) calculation demonstrates the reasonable diffusion pathway of K+ . In addition, the obtained WSe2 @N-doped C nanotubes have been used as anode material for lithium-ion batteries, which also show good rate performance and high cycle stability. Therefore, this work offers a new methodology for the ration design of new structure electrode materials with long cycle stability.

Iron Selenide-Based Heterojunction Construction and Defect Engineering for Fast Potassium/Sodium-Ion Storage.

Suitable anode materials with high capacity and long cycling stability, especially capability at high current densities, are urgently needed to advance the development of potassium ion batteries (PIBs) and sodium ion batteries (SIBs). Herein, a porous Ni-doped FeSe2 /Fe3 Se4 heterojunction encapsulated in Se-doped carbon (NF11 S/C) is designed through selenization of MOFs precursor. The porous composite possesses enriched active sites and facilitates transport for both ion and electron. Ni-doping is adopted to enrich the lattice defects and active sites. The Se-C bond and carbon framework endow integrity of the composite and hamper aggregation of selenide nano-particles during potassiation/de-potassiation. The NF11 S/C exhibits exceptional rate performance and ultra-long cycling stability (177.3 mA h g-1 after 3050 cycles at 2 A g-1 for PIBs and 208.8 mA h g-1 after 2000 cycles at 8 A g-1 for SIBs). The potassiation/de-potassiation mechanism is investigated via ex-situ X-ray powder diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectrocopy and Raman analysis. PTCDA//NF11 S/C full cell stably cycles for 1200 cycles at 200 mA g-1 with a capacity of 103.7 mA h g-1 , indicating the high application potential of the electrode for highly stable rechargeable batteries.

Anomalous Lattice Evolution-Mediated Electrical Properties in Transparent KNN-Based Lead-Free Ferroelectric Films.

The epitaxial (K0.49Na0.49Li0.02)(Ta0.2Nb0.8)O3 with 2 wt % MnO2 addition (KNNLT-M) film on the transparent La0.03Ba0.97SnO3-coated LaAlO3 (001) substrate is chosen to investigate how the lattice evolution, as well as the electrical properties, optical bandgap energy, and thermal stability, changes with the growth oxygen pressure [P(O2)]. Compared to the other perovskite oxide films, for example, (La,Ca)MnO3, PbTiO3, and BaTiO3, an anomalous lattice evolution with an increased (decreased) out-of-plane (in-plane) lattice constant was observed in KNNLT-M films as P(O2) increases. Such anomalous lattice evolution can improve the electric properties of KNNLT-M films; for example, the ferroelectricity is significantly optimized and the dielectric constant is enhanced from 451 to 1248 at 1 kHz. The X-ray photoelectron spectra results have demonstrated that high P(O2) can make more K cations to enter the perovskite lattice and the Mn2+/Mn3+ existing in KNNLT can effectively suppress the leakage behavior, thus promoting the electrical nature of KNNLT-M films. The optical measurements show that the KNNLT-M film heterostructures are highly transparent with a maximum transmittance of ∼80%, and both direct and indirect bandgap energies increase with increasing P(O2). Meanwhile, all these KNNLT-M films exhibit good thermal stability with stable ferroelectricity up to the high temperature of at least 125 °C. These results demonstrate that the control of the lattice structure and electrical properties by P(O2) is one of the important prerequisites for the application of KNN-based films.

Emerging two-dimensional nanomaterials for electrochemical nitrogen reduction.

Ammonia (NH3) is essential to serve as the biological building blocks for maintaining organism function, and as the indispensable nitrogenous fertilizers for increasing the yield of nutritious crops. The current Haber-Bosch process for industrial NH3 production is highly energy- and capital-intensive. In light of this, the electroreduction of nitrogen (N2) into valuable NH3, as an alternative, offers a sustainable pathway for the Haber-Bosch transition, because it utilizes renewable electricity and operates under ambient conditions. Identifying highly efficient electrocatalysts remains the priority in the electrochemical nitrogen reduction reaction (NRR), marking superior selectivity, activity, and stability. Two-dimensional (2D) nanomaterials with sufficient exposed active sites, high specific surface area, good conductivity, rich surface defects, and easily tunable electronic properties hold great promise for the adsorption and activation of nitrogen towards sustainable NRR. Therefore, this Review focuses on the fundamental principles and the key metrics being pursued in NRR. Based on the fundamental understanding, the recent efforts devoted to engineering protocols for constructing 2D electrocatalysts towards NRR are presented. Then, the state-of-the-art 2D electrocatalysts for N2 reduction to NH3 are summarized, aiming at providing a comprehensive overview of the structure-performance relationships of 2D electrocatalysts towards NRR. Finally, we propose the challenges and future outlook in this prospective area.

Effect of different thermal stimuli on improving microcirculation in the contralateral foot.

BACKGROUND: The lower extremities of the body often suffer from impaired microcirculation, particularly in the elderly or people with underlying conditions such as diabetes. Especially for people suffering from peripheral vascular diseases, skin lesions or wearing an external fixator in one side of limbs, direct contact treatments are not suitable for them to improve microcirculation. Heating the contralateral limb has been reported to improve blood flow in the impaired limb. However, its effect on plantar microvascular responses has not been previously investigated. Thus, the aim of this study was to explore how heating by warm bath and infrared radiation affects the circulations in the contralateral foot. Twelve healthy adults participated in this study and were randomly assigned to either placing the left foot in a warm bath or exposing it to infrared radiation for 10 min intervention every other day. The skin temperature (Temp) and skin blood flow (SBF) in the second metatarsal head of the contralateral foot were measured before and after the intervention. RESULTS: The results showed that both Temp (Bath: from 29.05 ± 3.56 °C to 31.03 ± 4.14 °C; Infrared: from 29.98 ± 3.86 °C to 31.07 ± 3.92 °C) and SBF (Bath: from 62.26 ± 48.12 PU to 97.76 ± 63.90 PU; Infrared: from 63.37 ± 39.88 PU to 85.27 ± 47.62 PU) in the contralateral foot were significantly increased after heating in both tests (p < 0.05). However, the contralateral SBF increased for 5 min after heating in warm bath test, but only for 1 min in infrared radiation test. CONCLUSIONS: The results of this study show that both heating methods are the effective at increasing contralateral Temp and SBF, but the warm bath has a stronger residual thermal effect.

The effects of different accumulated pressure-time integral stimuli on plantar blood flow in people with diabetes mellitus.

BACKGROUND: Exercise, especially weight-bearing exercise (e.g. walking), may affect plantar tissue viability due to prolonged repetitive high vertical and high shear pressure stimulus on the plantar tissue, and further induce development of diabetic foot ulcers (DFUs). This study aimed to investigate the effects of different accumulated pressure-time integral (APTI) stimuli induced by walking on plantar skin blood flow (SBF) responses in people with diabetes mellitus (DM). METHODS: A repeated measures design was used in this study. Two walking protocols (low APTI (73,000 kPa·s) and high APTI (73,000 × 1.5 kPa·s)) were randomly assigned to ten people with DM and twenty people without DM. The ratio of SBF measured by laser Doppler flowmetry after walking to that before (normalized SBF) was used to express the SBF responses. RESULTS: After low APTI, plantar SBF of people with DM showed a similar response to people without DM (P = 0.91). However, after high APTI, people with DM had a significantly lower plantar SBF compared to people without DM (P < 0.05). In people with DM, plantar SBF in the first 2 min after both APTI stimuli significantly decreased compared to plantar SBF before walking (P < 0.05). CONCLUSIONS: People with DM had a normal SBF response after low APTI walking but had an impaired SBF response after high APTI walking, which suggests that they should avoid weight-bearing physical activity with intensity more than 73,000 kPa·s and should rest for more than 2 min after weight-bearing physical activity to allow a full vasodilatory response to reduce risk of DFUs.

Uniaxial Strain-Controlled Ground States in Manganite Films.

Strongly correlated perovskite oxides exhibit a plethera of intriguing phenomena and stimulate a great potential for multifunctional device applications. Utilizing tunable uniaxial strain, rather than biaxial or anisotropic strain, delivered from the crystallography of a single crystal substrate to modify the ground state of strongly correlated perovskite oxides has rarely been addressed for phase-space control. Here, we show that the physical properties of La2/3Ca1/3MnO3 (LCMO) films are remarkably different depending on the crystallographic orientations of the orthorhombic NdGaO3 (NGO) substrates. More importantly, the antiferromagnetic charge-ordered insulating (COI) phase induced in the (100) or (001)-oriented LCMO films can be dramatically promoted (or suppressed) by a uniaxial tensile (or compressive) bending stress along the in-plane [010] direction. By contrast, the COI phase is nearly unaffected along the other transverse in-plane directions. Results from scanning transmission electron microscopy reveal that the (100)- or (001)-oriented LCMO films are uniaxially tensile strained along the [010] direction, while the LCMO/NGO(010) and LCMO/NGO(110) films remaining as a bulklike ferromagnetic metallic state exhibit a different strain state. Density functional theory calculations further reveal that the cooperatively increased Jahn-Teller distortion and charge ordering may be indispensible for the inducing and promoting of the COI phase. These findings provide a path to understand the correlation between local and extended structural distortions imparted by coherent epitaxy and the electronic states for quantum phase engineering.

[Estimation of lung recruitment characteristics using the static pressure-volume curve of lungs].

Mechanical ventilation is an importmant life-sustaining treatment for patients with acute respiratory distress syndrome. Its clinical outcomes depend on patients' characteristics of lung recruitment. Estimation of lung recruitment characteristics is valuable for the determination of ventilatory maneurvers and ventilator parameters. There is no easily-used, bedside method to assess lung recruitment characteristics. The present paper proposed a method to estimate lung recruitment characteristics from the static pressure-volume curve of lungs. The method was evaluated by comparing with published experimental data. Results of lung recruitment derived from the presented method were in high agreement with the published data, suggesting that the proposed method is capable to estimate lung recruitment characteristics. Since some advanced ventilators are capable to measure the static pressure-volume curve automatedly, the presented method is potential to be used at bedside, and it is helpful for clinicians to individualize ventilatory manuevers and the correpsonding ventilator parameters.

In-situ Nano-Crystallization and Solvation Modulation to Promote Highly Stable Anode Involving Alloy/De-alloy for Potassium Ion Batteries.

For advanced anode materials involving alloy/de-alloy chemistry for potassium ion batteries (PIBs), two-dimensional (2D) bismuth subcarbonate (BCO) nanosheets that possess high theoretical capacity of 631 mAh g-1 are proposed. The large lattice spacing of 0.683 nm along b axis facilitate insertion of K+ ion to boost high-capacity delivery of ca. 610 mAh g-1 , and the in situ nano-crystallization well ease volume changes of the integrated particle and shorten ion diffusion path during potassiation/depotassiation. After coupling with a concentrated KFSI-G2 electrolyte, the robust and efficient SEI built from enhanced participation of FSI- synergistically endow structural stability of the flower-like BCO, and enable a prolonged cycling performance with capacity of ca. 300 mAh g-1 at 0.2 A g-1 for 1500 cycles, achieving an ultralow decay rate of 0.007 %. Mechanistic investigations probe the electrochemistry involving alloy/de-alloy and phase transition of the electrode.

Willow-Leaf-Like ZnSe@N-Doped Carbon Nanoarchitecture as a Stable and High-Performance Anode Material for Sodium-Ion and Potassium-Ion Batteries.

ZnSe is regarded as a promising anode material for energy storage due to its high theoretical capacity and environment friendliness. Nevertheless, it is still a significant challenge to obtain superior electrode materials with stable performance owing to the serious volume change and aggregation upon cycling. Herein, a willow-leaf-like nitrogen-doped carbon-coated ZnSe (ZnSe@NC) composite synthesized through facile solvothermal and subsequent selenization process is beneficial to expose more active sites and facilitate the fast electron/ion transmission. These merits significantly enhance the electrochemical performances of ZnSe@NC for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). The obtained ZnSe@NC exhibits outstanding rate performance (440.3 mAh g-1 at 0.1 A g-1 and 144.4 mAh g-1 at 10 A g-1 ) and ultralong cycle stability (242.2 mAh g-1 at 8.0 A g-1 even after 3200 cycles) for SIBs. It is noted that 106.5 mAh g-1 can be retained after 550 cycles and 71.4 mAh g-1 is still remained after 1500 cycles at 200 mA g-1 when applied as anode for PIBs, indicating good cycle stability of the electrode. The possible electrochemical mechanism and the ionic diffusion kinetics of the ZnSe@NC are investigated using ex situ X-ray diffraction, high-resolution transmission electron microscopy, and a series of electrochemical analyses.

Mesoporous Tin-Based Oxide Nanospheres/Reduced Graphene Composites as Advanced Anodes for Lithium-Ion Half/Full Cells and Sodium-Ion Batteries.

The large volume variations of tin-based oxides hinder their extensive application in the field of lithium-ion batteries (LIBs). In this study, structure design, hybrid fabrication, and carbon-coating approaches have been simultaneously adopted to address these shortcomings. To this end, uniform mesoporous NiO/SnO2 @rGO, Ni-Sn oxide@rGO, and SnO2 @rGO nanosphere composites have been selectively fabricated. Among them, the obtained NiO/SnO2 @rGO composite exhibited a high capacity of 800 mAh g-1 at 1000 mA g-1 after 400 cycles. The electrochemical mechanism of NiO/SnO2 as an anode for LIBs has been preliminarily investigated by ex situ XRD pattern analysis. Furthermore, an NiO/SnO2 @rGO-LiCoO2 lithium-ion full cell showed a high capacity of 467.8 mAh g-1 at 500 mA g-1 after 100 cycles. Notably, the NiO/SnO2 @rGO composite also showed good performance when investigated as an anode for sodium-ion batteries (SIBs). It is believed that the unique mesoporous nanospherical framework, synergistic effects between the various components, and uniform rGO wrapping of NiO/SnO2 shorten the Li+ ion diffusion pathways, maintain sufficient contact between the active material and the electrolyte, mitigate volume changes, and finally improve the electrical conductivity of the electrode.

General Fabrication of Boride, Carbide, and Nitride Nanocrystals via a Metal-Hydrolysis-Assisted Process.

Metal boride, carbide, and nitride materials are useful owing to their wide variety of interesting chemical and physical properties. However, the synthesis of these materials with nano or mesoscale sizes is challenging due to the usually required high temperatures and long reaction durations. To our knowledge, the exploration of a number of simultaneous chemical reactions through rapid synthesis still remains a great challenge. In this study, a general route for the reduction and transformation of metal oxides into related metal boride (TiB2, MoB2, DyB4, ErB4, YB4, LaB6, CeB6, SmB6, EuB6), carbide (SiC, TiC, VC, WC, W2C, ZrC, MoC, NbC), and nitride (TiN, VN, BN, AlN, CrN, MgSiN2) nanocrystals were achieved at 150 °C. Here, the exothermic reaction of metal magnesium hydrolysis is utilized to assist the reaction in sealed stainless steel autoclaves. In situ temperature monitoring showed that the inside temperature increased quickly from 139 to 902 °C at the initial stage. The obtained products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), and high-resolution TEM techniques. The low reaction temperature and cheap raw materials make it possible for large-scale synthesis of those nanomaterials.