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1.
Respiration ; 103(7): 406-416, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38422997

RESUMEN

INTRODUCTION: Distinguishing between malignant pleural effusion (MPE) and benign pleural effusion (BPE) poses a challenge in clinical practice. We aimed to construct and validate a combined model integrating radiomic features and clinical factors using computerized tomography (CT) images to differentiate between MPE and BPE. METHODS: A retrospective inclusion of 315 patients with pleural effusion (PE) was conducted in this study (training cohort: n = 220; test cohort: n = 95). Radiomic features were extracted from CT images, and the dimensionality reduction and selection processes were carried out to obtain the optimal radiomic features. Logistic regression (LR), support vector machine (SVM), and random forest were employed to construct radiomic models. LR analyses were utilized to identify independent clinical risk factors to develop a clinical model. The combined model was created by integrating the optimal radiomic features with the independent clinical predictive factors. The discriminative ability of each model was assessed by receiver operating characteristic curves, calibration curves, and decision curve analysis (DCA). RESULTS: Out of the total 1,834 radiomic features extracted, 15 optimal radiomic features explicitly related to MPE were picked to develop the radiomic model. Among the radiomic models, the SVM model demonstrated the highest predictive performance [area under the curve (AUC), training cohort: 0.876, test cohort: 0.774]. Six clinically independent predictive factors, including age, effusion laterality, procalcitonin, carcinoembryonic antigen, carbohydrate antigen 125 (CA125), and neuron-specific enolase (NSE), were selected for constructing the clinical model. The combined model (AUC: 0.932, 0.870) exhibited superior discriminative performance in the training and test cohorts compared to the clinical model (AUC: 0.850, 0.820) and the radiomic model (AUC: 0.876, 0.774). The calibration curves and DCA further confirmed the practicality of the combined model. CONCLUSION: This study presented the development and validation of a combined model for distinguishing MPE and BPE. The combined model was a powerful tool for assisting in the clinical diagnosis of PE patients.


Asunto(s)
Derrame Pleural Maligno , Tomografía Computarizada por Rayos X , Humanos , Femenino , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Derrame Pleural Maligno/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Anciano , Diagnóstico Diferencial , Derrame Pleural/diagnóstico por imagen , Máquina de Vectores de Soporte , Curva ROC , Modelos Logísticos , Adulto , Radiómica
2.
Angew Chem Int Ed Engl ; 63(7): e202315624, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38151704

RESUMEN

Graphite (Gr) has been considered as the most promising anode material for potassium-ion batteries (PIBs) commercialization due to its high theoretical specific capacity and low cost. However, Gr-based PIBs remain unfeasible at low temperature (LT), suffering from either poor kinetics based on conventional carbonate electrolytes or K+ -solvent co-intercalation issue based on typical ether electrolytes. Herein, a high-performance Gr-based LT rechargeable PIB is realized for the first time by electrolyte chemistry. Applying unidentate-ether-based molecule as the solvent dramatically weakens the K+ -solvent interactions and lowers corresponding K+ de-solvation kinetic barrier. Meanwhile, introduction of steric hindrance suppresses co-intercalation of K+ -solvent into Gr, greatly elevating operating voltage and cyclability of the full battery. Consequently, the as-prepared Gr||prepotassiated 3,4,9,10-perylene-tetracarboxylicacid-dianhydride (KPTCDA) full PIB can reversibly charge/discharge between -30 and 45 °C with a considerable energy density up to 197 Wh kgcathode -1 at -20 °C, hopefully facilitating the development of LT PIBs.

3.
Chem Soc Rev ; 53(2): 684-713, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38116613

RESUMEN

Crystalline-amorphous hybrid materials (CA-HMs) possess the merits of both pure crystalline and amorphous phases. Abundant dangling bonds, unsaturated coordination atoms, and isotropic structural features in the amorphous phase, as well as relatively high electronic conductivity and thermodynamic structural stability of the crystalline phase simultaneously take effect in CA-HMs. Furthermore, the atomic and bandgap mismatch at the CA-HM interface can introduce more defects as extra active sites, reservoirs for promoted catalytic and electrochemical performance, and induce built-in electric field for facile charge carrier transport. Motivated by these intriguing features, herein, we provide a comprehensive overview of CA-HMs on various aspects-from synthetic methods to multiple applications. Typical characteristics of CA-HMs are discussed at the beginning, followed by representative synthetic strategies of CA-HMs, including hydrothermal/solvothermal methods, deposition techniques, thermal adjustment, and templating methods. Diverse applications of CA-HMs, such as electrocatalysis, batteries, supercapacitors, mechanics, optoelectronics, and thermoelectrics along with underlying structure-property mechanisms are carefully elucidated. Finally, challenges and perspectives of CA-HMs are proposed with an aim to provide insights into the future development of CA-HMs.

4.
J Bone Miner Metab ; 41(6): 877-889, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37898574

RESUMEN

INTRODUCTION: The aim of this analysis is to construct a combined model that integrates radiomics, clinical risk factors, and machine learning algorithms to diagnose osteoporosis in patients and explore its potential in clinical applications. MATERIALS AND METHODS: A retrospective analysis was conducted on 616 lumbar spine. Radiomics features were extracted from the computed tomography (CT) scans and anteroposterior and lateral X-ray images of the lumbar spine. Logistic regression (LR), support vector machine (SVM), and random forest (RF) algorithms were used to construct radiomics models. The receiver operating characteristic curve (ROC) was employed to select the best-performing model. Clinical risk factors were identified through univariate logistic regression analysis (ULRA) and multivariate logistic regression analysis (MLRA) and utilized to develop a clinical model. A combined model was then created by merging radiomics and clinical risk factors. The performance of the models was evaluated using ROC curve analysis, and the clinical value of the models was assessed using decision curve analysis (DCA). RESULTS: A total of 4858 radiomics features were extracted. Among the radiomics models, the SVM model demonstrated the optimal diagnostic capabilities and accuracy, with an area under the curve (AUC) of 0.958 (0.9405-0.9762) in the training cohort and 0.907 (0.8648-0.9492) in the test cohort. Furthermore, the combined model exhibited an AUC of 0.959 (0.9412-0.9763) in the training cohort and 0.910 (0.8690-0.9506) in the test cohort. CONCLUSION: The combined model displayed outstanding ability in diagnosing osteoporosis, providing a safe and efficient method for clinical decision-making.


Asunto(s)
Osteoporosis , Tomografía Computarizada por Rayos X , Humanos , Rayos X , Estudios Retrospectivos , Aprendizaje Automático , Osteoporosis/diagnóstico por imagen
5.
Inorg Chem ; 62(39): 15834-15841, 2023 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-37724987

RESUMEN

A highly sensitive detection of ultraviolet (UV) radiation is required in a broad range of scientific research, chemical industries, and health-related applications. Traditional UV photodetectors fabricated by direct wide-band-gap inorganic semiconductors often suffer from several disadvantages such as complicated manufacturing procedures, requiring multiple operations and high-cost instruments to obtain a readout. Searching for new materials or simple strategies to develop UV dosimeters for quantitative, accurate, and on-site detection of UV radiation dose is still highly desirable. Herein, a photochromic uranyl-based coordination polymer [(UO2)(PBPCA)·DMF]·DMF (PBPCA = pyridine-3,5-bis(phenyl-4-carboxylate), DMF = N,N'-dimethylformamide, denoted as SXU-1) with highly radiolytic and chemical stabilities was successfully synthesized via the solvothermal method at 100 °C. Surprisingly, the fresh samples of SXU-1 underwent an ultra-fast UV-induced (365 nm, 2 mW) color variation from yellow to orange in less than 1 s, and then the color changed further from orange to brick red after the subsequent irradiation, inspiring us to develop a colorimetric dosimeter based on red-green-blue (RGB) parameters. The mechanism of radical-induced photochromism was intensively investigated by UV-vis absorption spectra, EPR analysis, and SC-XRD data. Furthermore, SXU-1 was incorporated into an optoelectronic device to fabricate a novel dosimeter for convenient, quantitative, and on-site detection of UV radiation dose.

6.
Nat Commun ; 14(1): 6006, 2023 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-37752165

RESUMEN

In contrast to conventional batteries, anode-free configurations can extend cell-level energy densities closer to the theoretical limit. However, realizing alkali metal plating/stripping on a bare current collector with high reversibility is challenging, especially at low temperature, as an unstable solid-electrolyte interphase and uncontrolled dendrite growth occur more easily. Here, a low-temperature anode-free potassium (K) metal non-aqueous battery is reported. By introducing Si-O-based additives, namely polydimethylsiloxane, in a weak-solvation low-concentration electrolyte of 0.4 M potassium hexafluorophosphate in 1,2-dimethoxyethane, the in situ formed potassiophilic interface enables uniform K deposition, and offers K||Cu cells with an average K plating/stripping Coulombic efficiency of 99.80% at -40 °C. Consequently, anode-free Cu||prepotassiated 3,4,9,10-perylene-tetracarboxylicacid-dianhydride full batteries achieve stable cycling with a high specific energy of 152 Wh kg-1 based on the total mass of the negative and positive electrodes at 0.2 C (26 mA g-1) charge/discharge and -40 °C.

7.
Adv Mater ; 35(42): e2305314, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37652150

RESUMEN

Understanding and controlling crystallization is crucial for high-quality perovskite films and efficient solar cells. Herein, the issue of defects in formamidinium lead iodide (FAPbI3 ) formation is addressed, focusing on the role of intermediates. A comprehensive picture of structural and carrier evolution during crystallization is demonstrated using in situ grazing-incidence wide-angle X-ray scattering, ultraviolet-visible spectroscopy and photoluminescence spectroscopy. Three crystallization stages are identified: precursors to the δ-FAPbI3 intermediate, then to α-FAPbI3 , where defects spontaneously emerge. A hydrogen-sulfate-based ionic liquid additive is found to enable the phase-conversion pathway of precursors → solvated intermediates → α-FAPbI3 , during which the spontaneous generation of δ-FAPbI3 can be effectively circumvented. This additive extends the initial growth kinetics and facilitates solvent-FA+ ion exchange, which results in the self-elimination of defects during crystallization. Therefore, the improved crystallization dynamics lead to larger grain sizes and fewer defects within thin films. Ultimately, the improved perovskite crystallization dynamics enable high-performance solar cells, achieving impressive efficiencies of 25.14% at 300 K and 26.12% at 240 K. This breakthrough might open up a new era of application for the emerging perovskite photovoltaic technology to low-temperature environments such as near-space and polar regions.

8.
Angew Chem Int Ed Engl ; 62(29): e202306360, 2023 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-37211534

RESUMEN

Periodically arranging coordination-distinct actinides into one crystalline architecture is intriguing but of great synthetic challenge. We report a rare example of a heterobimetallic actinide metal-organic framework (An-MOF) by a unique reaction-induced preorganization strategy. A thorium MOF (SCU-16) with the largest unit cell among all Th-MOFs was prepared as the precursor, then the uranyl was precisely embedded into the MOF precursor under oxidation condition. Single crystal of the resulting thorium-uranium MOF (SCU-16-U) shows that a uranyl-specific site was in situ induced by the formate-to-carbonate oxidation reaction. The heterobimetallic SCU-16-U exhibits multifunction catalysis properties derived from two distinct actinides. The strategy proposed here offers a new avenue to create mixed-actinide functional material with unique architecture and versatile functionality.

9.
J Am Chem Soc ; 145(9): 5578-5588, 2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36812014

RESUMEN

High-energy radiation that is compatible with renewable energy sources enables direct H2 production from water for fuels; however, the challenge is to convert it as efficiently as possible, and the existing strategies have limited success. Herein, we report the use of Zr/Hf-based nanoscale UiO-66 metal-organic frameworks as highly effective and stable radiation sensitizers for purified and natural water splitting under γ-ray irradiation. Scavenging and pulse radiolysis experiments with Monte Carlo simulations show that the combination of 3D arrays of ultrasmall metal-oxo clusters and high porosity affords unprecedented effective scattering between secondary electrons and confined water, generating increased precursors of solvated electrons and excited states of water, which are the main species responsible for H2 production enhancement. The use of a small quantity (<80 mmol/L) of UiO-66-Hf-OH can achieve a γ-rays-to-hydrogen conversion efficiency exceeding 10% that significantly outperforms Zr-/Hf-oxide nanoparticles and the existing radiolytic H2 promoters. Our work highlights the feasibility and merit of MOF-assisted radiolytic water splitting and promises a competitive method for creating a green H2 economy.

10.
Nanomaterials (Basel) ; 12(23)2022 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-36500856

RESUMEN

Organic-inorganic lead halide perovskite is widely used in the photoelectric field due to its excellent photoelectric characteristics. Among them, perovskite single crystals have attracted much attention due to its lower trap density and better carrier transport capacity than their corresponding polycrystalline materials. Owing to these characteristics, perovskite single crystals have been widely used in solar cells, photodetectors, light-emitting diode (LED), and so on, which have greater potential than polycrystals in a series of optoelectronic applications. However, the fabrication of single-crystal devices is limited by size, thickness, and interface problems, which makes the development of single-crystal devices inferior to polycrystalline devices, which also limits their future development. Here, several representative optoelectronic applications of perovskite single crystals are introduced, and some existing problems and challenges are discussed. Finally, we outlook the growth mechanism of single crystals and further the prospects of perovskite single crystals in the further field of microelectronics.

11.
Nanomaterials (Basel) ; 12(24)2022 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-36558248

RESUMEN

Heavy metal pollution in river and lake sediments seriously damages river ecological safety and indirectly affects human health. The existing research mainly focuses on how to adsorb pollutants and repair sediment, and how the reuse of these pollutants may be a new technology to control sediment pollutants. The rapid development of perovskite solar cells in recent years has attracted a lot of attention, among which lead (Pb) halide perovskites have very excellent photoelectric performance. In this study, we propose a novel idea of introducing indium (In)-based perovskite to replace Pb (II) ions dispersed in river and lake sediment. Three sediment samples from a river in Shanghai Peace Park were collected to analyze the distribution of heavy metal Pb. We mixed the digestion solution of sediment with the prepared CH3NH3(MA)InICl2 solution and found that indium (In) in perovskite precursor solution would be gradually replaced by Pb in sediments. An in situ synchrotron radiation XRD experiment was performed to reveal the reaction mechanism of solutions and provide a good research platform for the comprehensive reuse of sediment in the future. This study provides a new method of remediation of heavy metal pollution in river and lake sediments.

12.
Dalton Trans ; 51(40): 15233-15238, 2022 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-36190512

RESUMEN

A three-dimensional microporous thorium-based metal-organic framework (Th-BPYDC-I) that features a suitable pore size for Xe was prepared. The pore confinement effect enables high Xe uptake (2.15 mmol g-1) and good Xe/Kr selectivity (7.49). This work highlights the critical role of the size-matching rule in noble gas separation and provides an alternative option for Xe/Kr separation.

13.
Front Public Health ; 10: 976221, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36148347

RESUMEN

The association of IFN-γ receptor 1 (IFNGR1) gene polymorphisms with tuberculosis (TB) susceptibility has not been systematically studied. We therefore conducted a meta-analysis to assess their association. Literature search was conducted in PubMed, EMBASE, Web of Science, and the Cochrane Library. Odds ratio (OR) and 95% confidence interval (CI) was pooled by the random-effect model. Statistical analyses were performed using STATA 12.0 software. Fourteen studies involved 7,699 TB cases and 8,289 controls were included in this meta-analysis. A significant association was found between the IFNGR1 rs2234711 polymorphism and TB susceptibility among Africans in dominant model (OR = 1.24, 95%CI:1.01-1.52), and among Asians in allele model (OR = 0.89, 95%CI: 0.79-0.99), homozygote model (OR = 0.82, 95%CI: 0.70-0.98) and additive model (OR = 0.90, 95%CI: 0.83-0.97). In addition, a significant association was observed between the IFNGR1 rs7749390 polymorphism and TB susceptibility among Africans in allele model (OR = 0.89, 95%CI: 0.82-0.98). No significant association was found between the IFNGR1 rs1327474 polymorphism and TB susceptibility. In summary, IFNGR1 rs2234711 polymorphism was associated with increased TB susceptibility in Africans and decreased TB susceptibility in Asians, while IFNGR1 rs7749390 polymorphism was associated with decreased TB susceptibility in Africans.


Asunto(s)
Predisposición Genética a la Enfermedad , Tuberculosis , Humanos , Polimorfismo Genético , Receptores de Interferón/genética , Tuberculosis/genética , Receptor de Interferón gamma
14.
ACS Nano ; 16(10): 15770-15778, 2022 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-36066564

RESUMEN

Reliable power supplies at extremely high temperatures are urgently needed to broaden the application scenarios for electric devices. Aqueous zinc metal batteries (ZMBs) with intrinsic safety are a promising alterative for high-temperature energy storage. However, the reversibility and long-term cycling stability of aqueous ZMBs at extremely high temperatures (≥100 °C) have rarely been explored. Herein, we reveal that spontaneous Zn corrosion and severe electrochemical hydrogen evolution at high temperature are vital restrictions for traditional aqueous ZMBs. To address this, a crowding agent, 1,5-pentanediol, was introduced into an aqueous electrolyte to suppress water reactivity by strengthening O-H bonds of H2O and decreasing H2O content in the Zn2+ solvation sheath, while maintaining flame resistance of the electrolyte. Importantly, this electrolyte enabled reversible Zn deposition with a Coulombic efficiency of 98.1% and a long cycling life of Zn//Zn batteries for over 500 cycles (at 1 mA cm-2 and 0.5 mAh cm-2) at 100 °C. Moreover, stable cycling of Zn//Te full batteries at 100 °C was demonstrated.

15.
Small ; 18(26): e2202214, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35623998

RESUMEN

Zn anode is confronted with serious Zn dendrite growth and water-induced parasitic reactions, which severely hinders the rapid development and practical application of aqueous zinc metal batteries (AZMBs). Herein, inspired by sodium hyaluronate (SH) biomolecules in living organisms featured with the functions of water retention, ion-transport regulation, and film-formation, the SH working as a dynamic and self-adaptive "mask" is proposed to stabilize Zn anode. Benefiting from the abundant functional groups with high hydrophilicity and zincophilicity, SH molecule can constrain active water molecules on the Zn-electrolyte interface and participate in Zn2+ solvation structure to suppress parasitic reactions. Furthermore, the dynamical adsorption of SH with high-density negative charge on the Zn surface could serve as Zn2+ reservoirs to guide uniform Zn deposition. Consequently, stable Zn plating and an ultrahigh cumulative plating capacity (CPC) of 4.8 Ah cm-2 are achieved even at 20 mA cm-2 (20 mAh cm-2 ) in a Zn||Zn symmetric battery, reaching a record level in AZMBs. In addition, the Zn||ß-MnO2 full battery exhibits a substantially improved cycle stability. This work presents a route to realize a highly reversible and stable Zn metal anode by learning from nature.


Asunto(s)
Compuestos de Manganeso , Óxidos , Electrodos , Zinc
16.
Phys Chem Chem Phys ; 24(7): 4620-4625, 2022 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-35132975

RESUMEN

Orthorhombic KFeO2 has a unique structure where K+ cations can migrate inside the Fe-O skeleton, thus making it a promising material for heterogeneous catalysis and electrochemical energy storage devices. However, KFeO2 is sensitive to conditions such as moisture and carbon dioxide, which would trigger severe phase evolution and consequently deteriorate the performance. In this work, we investigated the phase evolution using freshly prepared KFeO2 and KFeO2 after exposure to ambient air and after immersion in water, respectively. We found that the phase evolution of KFeO2 was composed of K-redistribution and phase transition, both of which originated from K+ extraction. We observed that K+ cations were extracted after exposing KFeO2 to ambient air, resulting in the formation of K2CO3·1.5 H2O outside KFeO2 and lattice expansion inside KFeO2. We also observed that water molecules were crucial to K+ extraction when calculating the function between potassium and the adjacent oxygen atoms via ab initio molecular dynamics simulations. Moreover, we successfully reinserted K+ cations into lattice expanded KFeO2 by high-temperature calcination at 900 °C; such a reversible extraction-insertion process would have great potential for application in catalyst reactivation and rechargeable high-temperature batteries.

17.
J Am Chem Soc ; 144(5): 2189-2196, 2022 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-35073062

RESUMEN

Exciton behaviors including exciton formation and dissociation dynamics play an essential role in the optoelectronic performance of semiconductive materials but remain unexplored in semiconductive metal-organic frameworks (MOFs). Herein, we reveal that the exciton behaviors in semiconductive MOFs can be regulated by framework-guest interactions, a feature often not achievable in traditional inorganic or organic semiconductors. Incorporation of the electron-deficient molecule within the pores of a terbium-based semiconductive MOF (Tb2L2·4H2O·6DMF, L = TATAB3-, 4,4',4″-s-triazine-1,3,5-triyltri-p-aminobenzoate, DMF = N,N-dimethylformamide) results in efficient energy transfer from the MOF skeleton to molecular acceptors, with a yield of up to 77.4%. This interaction facilitates distinctive exciton type conversion, giving rise to modified conductivity and photoelectric performance. We further fabricated a MOF-based X-ray detection device to demonstrate how the new architecture bolsters the optoelectronic efficiency, which outperforms the properties of parent semiconductive MOFs, with more than 60 times and 40 times enhancement of the photocurrent on-off ratio and detection sensitivity, respectively. With judiciously optimized exciton behaviors, the detection device exhibits a high sensitivity of 51.9 µC Gyair-1 cm-2 and records a charge carrier mobility-lifetime product of 1.12 × 10-3 cm2 V-1 among MOF-based X-ray detectors, which are competitive with values for commercially available detectors. These findings demonstrate a rational synthetic approach to designing exciton arrangements to improve the optoelectronic efficiency of semiconductive MOFs.

18.
J Colloid Interface Sci ; 607(Pt 2): 1262-1268, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34571310

RESUMEN

Organic materials are attracting extensive attention as promising cathodes for rechargeable aqueous zinc-ion batteries (ZIBs). However, most of them fail to implement the requirement of batteries with combined high-rate and long-cycle performance. Herein, we report a flexible organic molecule 2,3-diaminophenazine (DAP) which exhibits ultrahigh rate performance up to 500C and high capacity retention of 80% after 10,000 cycles at 100C (25.5 A g-1). Moreover, the Zn2+ storage mechanism in the DAP electrode is revealed by ex-situ characterization technologies and theoretical calculation, and the redox active centers CN participate in the reversible electrochemical reaction process. Furthermore, electrochemical analyses show that surface-controlled electrochemical behavior contributes to the high-rate performance of DAP cathodes. Besides, its excellent long-cycle performance can be ascribed to the suppressed DAP dissolubility by using a modified glass fiber separator with carbon nanotubes (CNT) film. Our work provides useful insight into the design of high-rate and long-life ZIBs.

19.
ACS Appl Mater Interfaces ; 13(45): 54096-54105, 2021 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-34749501

RESUMEN

Aqueous zinc-ion batteries (ZIBs) are regarded as a promising candidate for ultrafast charge storage owing to the high ionic conductivity of aqueous electrolytes and high theoretical capacity of zinc metal anodes. However, the strong electrostatic interaction between high-charge-density zinc ions and host materials generally leads to sluggish ion-transport kinetics and structural collapse of rigid cathode materials during the charge/discharge process, so searching for suitable cathode materials for ultrafast and long-term stable ZIBs remains a great challenge. Herein, flexible electron-rich ion channels enabling fast-charging and stable aqueous ZIBs have been demonstrated. Because of the nitrogen-rich conjugated structure of organic phenazine (PNZ) molecules, electron-rich ion channels are formed with the C═N redox centers situated on the channel surface, where zinc ions can transport rapidly and react with active moieties directly. Meanwhile, the π-conjugated systems and inherent flexibility of PNZ molecules can accommodate rapid strain changes and maintain their structural stability during zinc-ion intercalation/deintercalation. Consequently, they exhibit a high capacity of 94.2 mAh g-1 at an ultrahigh rate of 700C (208.6 A g-1) and an ultralong life over 100,000 cycles at 100C, which are superior to those of previously reported aqueous ZIBs. Our work presents a new way for developing ultrafast and ultrastable aqueous ZIBs.

20.
Materials (Basel) ; 14(19)2021 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-34639931

RESUMEN

Substantial effort has been devoted to fabricating nanocrystalline lanthanum ferrite (LaFeO3), and calcination is the crucial process of crystallization in both high-temperature strategies and wet chemical methods. Lowering the calcination temperature gives the ability to resist the growth and agglomeration of nanoparticles, therefore contributing to preserve their unique nanostructures and properties. In this work, we prepared crystalline LaFeO3 nanoparticles with a calcination process at 500 °C, lower than the calcination temperature required in most wet chemistry methods. Correspondingly, the experimental conditions, including stoichiometric ratios, pH values, precipitants, complexant regent, and the calcination temperatures, were investigated. We found that the crystalline LaFeO3 was formed with crystalline NaFeO2 after calcination at 500 °C. Furthermore, the structure of FeO6 octahedra that formed in coprecipitation was associated with the process of crystallization, which was predominantly determined by calcination temperature. Moreover, an illusion of pure-phase LaFeO3 was observed when investigated by X-ray diffraction spectroscopy, which involves amorphous sodium ferrite or potassium ferrite, respectively. These findings can help prepare nanostructured perovskite oxides at low calcination temperatures.

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