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1.
Proc Natl Acad Sci U S A ; 121(17): e2311075121, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38625942

RESUMO

Voltage oscillation at subzero in sodium-ion batteries (SIBs) has been a common but overlooked scenario, almost yet to be understood. For example, the phenomenon seriously deteriorates the performance of Na3V2(PO4)3 (NVP) cathode in PC (propylene carbonate)/EC (ethylene carbonate)-based electrolyte at -20 °C. Here, the correlation between voltage oscillation, structural evolution, and electrolytes has been revealed based on theoretical calculations, in-/ex-situ techniques, and cross-experiments. It is found that the local phase transition of the Na3V2(PO4)3 (NVP) cathode in PC/EC-based electrolyte at -20 °C should be responsible for the oscillatory phenomenon. Furthermore, the low exchange current density originating from the high desolvation energy barrier in NVP-PC/EC system also aggravates the local phase transformation, resulting in severe voltage oscillation. By introducing the diglyme solvent with lower Na-solvent binding energy, the voltage oscillation of the NVP can be eliminated effectively at subzero. As a result, the high capacity retentions of 98.3% at -20 °C and 75.3% at -40 °C are achieved. The finding provides insight into the abnormal SIBs degradation and brings the voltage oscillation behavior of rechargeable batteries into the limelight.

2.
Plant J ; 119(2): 982-997, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38743909

RESUMO

Low temperature (LT) greatly restricts grain filling in maize (Zea mays L.), but the relevant molecular mechanisms are not fully understood. To better understand the effect of LT on grain development, 17 hybrids were subjected to LT stress in field trials over 3 years, and two hybrids of them with contrasting LT responses were exposed to 30/20°C and 20/10°C for 7 days during grain filling in a greenhouse. At LT, thousand-kernel weight declined, especially in LT-sensitive hybrid FM985, while grain-filling rate was on average about 48% higher in LT-tolerant hybrid DK159 than FM985. LT reduced starch synthesis in kernel mainly by suppression of transcript levels and enzyme activities for sucrose synthase and hexokinase. Brassinolide (BR) was abundant in DK159 kernel, and genes involved in BR and cytokinin signals were inducible by stress. LT downregulated the genes in light-harvesting complex and photosystem I/II subunits, accompanied by reduced photosynthetic rate and Fv/Fm in ear leaf. The LT-tolerant hybrid could maintain a high soluble sugar content and fast interconversion between sucrose and hexose in the stem internode and cob, improving assimilate allocation to kernel at LT stress and paving the way for simultaneous growth and LT stress responses.


Assuntos
Temperatura Baixa , Regulação da Expressão Gênica de Plantas , Zea mays , Zea mays/crescimento & desenvolvimento , Zea mays/genética , Zea mays/metabolismo , Zea mays/fisiologia , Glucosiltransferases/metabolismo , Glucosiltransferases/genética , Fotossíntese , Amido/metabolismo , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/genética , Grão Comestível/fisiologia , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Sementes/crescimento & desenvolvimento , Sementes/genética , Sementes/metabolismo , Brassinosteroides/metabolismo , Esteroides Heterocíclicos/farmacologia , Esteroides Heterocíclicos/metabolismo
3.
Plant J ; 119(3): 1433-1448, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38922743

RESUMO

Anthocyanins are natural pigments and dietary antioxidants that play multiple biological roles in plants and are important in animal and human nutrition. Low temperature (LT) promotes anthocyanin biosynthesis in many species including blood orange. A retrotransposon in the promoter of Ruby1, which encodes an R2R3 MYB transcription factor, controls cold-induced anthocyanin accumulation in blood orange flesh. However, the specific mechanism remains unclear. In this study, we characterized two LT-induced ETHYLENE RESPONSE FACTORS (CsERF054 and CsERF061). Both CsERF054 and CsERF061 can activate the expression of CsRuby1 by directly binding to a DRE/CRT cis-element within the retrotransposon in the promoter of CsRuby1, thereby positively regulating anthocyanin biosynthesis. Further investigation indicated that CsERF061 also forms a protein complex with CsRuby1 to co-activate the expression of anthocyanin biosynthetic genes, providing a dual mechanism for the upregulation of the anthocyanin pathway. These results provide insights into how LT mediates anthocyanin biosynthesis and increase the understanding of the regulatory network of anthocyanin biosynthesis in blood orange.


Assuntos
Antocianinas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Regiões Promotoras Genéticas , Retroelementos , Fatores de Transcrição , Antocianinas/biossíntese , Antocianinas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Retroelementos/genética , Etilenos/metabolismo , Etilenos/biossíntese , Temperatura Baixa , Citrus/genética , Citrus/metabolismo
4.
Nano Lett ; 24(19): 5729-5736, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38708832

RESUMO

Quantum-dot light-emitting diodes (QLEDs), a kind of promising optoelectronic device, demonstrate potential superiority in next-generation display technology. Thermal cross-linked hole transport materials (HTMs) have been employed in solution-processed QLEDs due to their excellent thermal stability and solvent resistance, whereas the unbalanced charge injection and high cross-linking temperature of cross-linked HTMs can inhibit the efficiency of QLEDs and limit their application. Herein, a low-temperature cross-linked HTM of 4,4'-bis(3-(((4-vinylbenzyl)oxy)methyl)-9H-carbazol-9-yl)-1,1'-biphenyl (DV-CBP) with a flexible styrene side chain is introduced, which reduces the cross-linking temperature to 150 °C and enhances the hole mobility up to 1.01 × 10-3 cm2 V-1 s-1. More importantly, the maximum external quantum efficiency of 21.35% is successfully obtained on the basis of the DV-CBP as a cross-linked hole transport layer (HTL) for blue QLEDs. The low-temperature cross-linked high-mobility HTL using flexible side chains could be an excellent alternative for future HTL development.

5.
Nano Lett ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38856230

RESUMO

Lithium metal batteries utilizing lithium metal as the anode can achieve a greater energy density. However, it remains challenging to improve low-temperature performance and fast-charging features. Herein, we introduce an electrolyte solvation chemistry strategy to regulate the properties of ethylene carbonate (EC)-based electrolytes through intermolecular interactions, utilizing weakly solvated fluoroethylene carbonate (FEC) to replace EC, and incorporating the low-melting-point solvent 1,2-difluorobenzene (2FB) as a diluent. We identified that the intermolecular interaction between 2FB and solvent can facilitate Li+ desolvation and lower the freezing point of the electrolyte effectively. The resulting electrolyte enables the LiNi0.8Co0.1Mn0.1O2||Li cell to operate at -30 °C for more than 100 cycles while delivering a high capacity of 154 mAh g-1 at 5.0C. We present a solvation structure and interfacial model to analyze the behavior of the formulated electrolyte composition, establishing a relationship with cell performance and also providing insights for the electrolyte design under extreme conditions.

6.
Nano Lett ; 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39038223

RESUMO

This study delves into the intriguing properties of the 1H/1T-TaS2 van der Waals heterostructure, focusing on the transparency of the 1H layer to the charge density wave of the underlying 1T layer. Despite the sizable interlayer separation and metallic nature of the 1H layer, positive bias voltages result in a pronounced superposition of the 1T charge density wave structure on the 1H layer. The conventional explanation relying on tunneling effects proves insufficient. Through a comprehensive investigation combining low-temperature scanning tunneling microscopy, scanning tunneling spectroscopy, non-contact atomic force microscopy, and first-principles calculations, we propose an alternative interpretation. The transparency effect arises from a weak yet substantial electronic coupling between the 1H and 1T layers, challenging prior understanding of the system. Our results highlight the critical role played by interlayer electronic interactions in van der Waals heterostructures to determine the final ground states of the systems.

7.
Plant J ; 115(1): 205-219, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36999610

RESUMO

Low temperature and abscisic acid (ABA) are the two main factors that induce anthocyanin synthesis; however, their potential relationships in governing anthocyanin biosynthesis in Solanum lycopersicum (tomato) seedlings remains unclear. Our study revealed the involvement of the transcription factor SlAREB1 in the low-temperature response of tomato seedlings via the ABA-dependent pathway, for a specific temperature range. The overexpression of SlAREB1 enhanced the expression of anthocyanin-related genes and the accumulation of anthocyanins, especially under low-temperature conditions, whereas silencing SlAREB1 dramatically reduced gene expression and anthocyanin accumulation. There is a direct interaction between SlAREB1 and the promoters of SlDFR and SlF3'5'H, which are structural genes that impact anthocyanin biosynthesis. SlAREB1 can regulate anthocyanins through controlling SlDFR and SlF3'5'H expression. Accordingly, SlAREB1 takes charge of regulating anthocyanin biosynthesis in tomato seedlings via the ABA-dependent pathway at low temperatures.


Assuntos
Solanum lycopersicum , Solanum lycopersicum/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Antocianinas , Temperatura , Ácido Abscísico/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
8.
BMC Genomics ; 25(1): 283, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38500027

RESUMO

MYB transcription factors play an extremely important regulatory role in plant responses to stress and anthocyanin synthesis. Cloning of potato StMYB-related genes can provide a theoretical basis for the genetic improvement of pigmented potatoes. In this study, two MYB transcription factors, StMYB113 and StMYB308, possibly related to anthocyanin synthesis, were screened under low-temperature conditions based on the low-temperature-responsive potato StMYB genes family analysis obtained by transcriptome sequencing. By analyzed the protein properties and promoters of StMYB113 and StMYB308 and their relative expression levels at different low-temperature treatment periods, it is speculated that StMYB113 and StMYB308 can be expressed in response to low temperature and can promote anthocyanin synthesis. The overexpression vectors of StMYB113 and StMYB308 were constructed for transient transformation tobacco. Color changes were observed, and the expression levels of the structural genes of tobacco anthocyanin synthesis were determined. The results showed that StMYB113 lacking the complete MYB domain could not promote the accumulation of tobacco anthocyanins, while StMYB308 could significantly promote the accumulation involved in tobacco anthocyanins. This study provides a theoretical reference for further study of the mechanism of StMYB113 and StMYB308 transcription factors in potato anthocyanin synthesis.


Assuntos
Solanum tuberosum , Fatores de Transcrição , Fatores de Transcrição/metabolismo , Solanum tuberosum/genética , Solanum tuberosum/metabolismo , Antocianinas , Temperatura , Proteínas de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas/genética
9.
BMC Genomics ; 25(1): 370, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627628

RESUMO

BACKGROUND: Quinoa (Chenopodium quinoa Willd.) is valued for its nutritional richness. However, pre-harvest sprouting poses a significant threat to yield and grain quality. This study aims to enhance our understanding of pre-harvest sprouting mitigation strategies, specifically through delayed sowing and avoiding rainy seasons during quinoa maturation. The overarching goal is to identify cold-resistant varieties and unravel the molecular mechanisms behind the low-temperature response of quinoa. We employed bioinformatics and genomics tools for a comprehensive genome-wide analysis of polyamines (PAs) and ethylene synthesis gene families in quinoa under low-temperature stress. RESULTS: This involved the identification of 37 PA biosynthesis and 30 PA catabolism genes, alongside 227 ethylene synthesis. Structural and phylogenetic analyses showcased conserved patterns, and subcellular localization predictions indicated diverse cellular distributions. The results indicate that the PA metabolism of quinoa is closely linked to ethylene synthesis, with multiple genes showing an upregulation in response to cold stress. However, differential expression within gene families suggests a nuanced regulatory network. CONCLUSIONS: Overall, this study contributes valuable insights for the functional characterization of the PA metabolism and ethylene synthesis of quinoa, which emphasize their roles in plant low-temperature tolerance and providing a foundation for future research in this domain.


Assuntos
Chenopodium quinoa , Chenopodium quinoa/genética , Chenopodium quinoa/metabolismo , Filogenia , Temperatura , Poliaminas/metabolismo , Etilenos/metabolismo
10.
Curr Issues Mol Biol ; 46(7): 6508-6521, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-39057030

RESUMO

Chloroplasts are organelles responsible for photosynthesis in plants, providing energy for growth and development. However, the genetic regulatory mechanisms underlying early chloroplast development in rice remain incompletely understood. In this study, we identified a rice seedling thermosensitive chlorophyll-deficient mutant, osltsa8, and the genetic analysis of two F2 populations suggested that this trait may be controlled by more than one pair of alleles. Through reciprocal F2 populations and QTL-seq technology, OsLTSA8 was mapped to the interval of 24,280,402-25,920,942 bp on rice chromosome 8, representing a novel albino gene in rice. Within the candidate gene region of OsLTSA8, there were 258 predicted genes, among which LOC_Os08g39050, LOC_Os08g39130, and LOC_Os08g40870 encode pentatricopeptide repeat (PPR) proteins. RNA-seq identified 18 DEGs (differentially expressed genes) within the candidate interval, with LOC_Os08g39420 showing homology to the pigment biosynthesis-related genes Zm00001d017656 and Sb01g000470; LOC_Os08g39430 and LOC_Os08g39850 were implicated in chlorophyll precursor synthesis. RT-qPCR was employed to assess the expression levels of LOC_Os08g39050, LOC_Os08g39130, LOC_Os08g40870, LOC_Os08g39420, LOC_Os08g39430, and LOC_Os08g39850 in the wild-type and mutant plants. Among them, the differences in the expression levels of LOC_Os08g39050 and LOC_Os08g39430 were the most significant. This study will contribute to further elucidating the molecular mechanisms of rice chloroplast development.

11.
Plant Cell Physiol ; 2024 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-39096526

RESUMO

Low temperature significantly inhibits the plant growth in wheat (Triticum aestivum L.), prompting the exploration of effective strategies to mitigate low temperature stress. Several priming methods enhance low temperature stress tolerant, however, the role of ozone priming remains unclear in wheat. Here we found ozone priming alleviated low temperature stress in wheat. Transcriptome analysis showed that ozone priming positively modulated 'photosynthesis-antenna proteins' pathway in wheat under low temperature. Which was confirmed by the results of the ozone-primed plants had higher trapped energy flux and electron transport flux per reaction, and less damage to chloroplasts than non-primed plants under low temperature. Ozone priming also mitigated the overstimulation of glutathione metabolism and induced the accumulation of total ascorbic acid and glutathione, maintained redox homeostasis in wheat under low temperature. Moreover, gene expressions and enzyme activities in glycolysis pathways were upregulated in ozone priming comparing with non-priming after the low temperature stress. Furthermore, exogenous antibiotics significantly increased low temperature tolerance, which further proved that the inhibition of ribosome biogenesis by ozone priming was involved in low temperature tolerance in wheat. In conclusion, ozone priming enhanced wheat low temperature tolerance through promoting light-harvesting capacity, redox homeostasis, and carbohydrate metabolism, as well as inhibiting ribosome biogenesis.

12.
BMC Plant Biol ; 24(1): 536, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38862890

RESUMO

BACKGROUND: The heavy metal-associated isoprenylated plant protein (HIPP) is an important regulatory element in response to abiotic stresses, especially playing a key role in low-temperature response. RESULTS: This study investigated the potential function of PavHIPP16 up-regulated in sweet cherry under cold stress by heterologous overexpression in tobacco. The results showed that the overexpression (OE) lines' growth state was better than wild type (WT), and the germination rate, root length, and fresh weight of OE lines were significantly higher than those of WT. In addition, the relative conductivity and malondialdehyde (MDA) content of the OE of tobacco under low-temperature treatment were substantially lower than those of WT. In contrast, peroxidase (POD), superoxide dismutase (SOD), catalase (CAT) activities, hydrogen peroxide (H2O2), proline, soluble protein, and soluble sugar contents were significantly higher than those of WT. Yeast two-hybrid assay (Y2H) and luciferase complementation assay verified the interactions between PavbHLH106 and PavHIPP16, suggesting that these two proteins co-regulated the cold tolerance mechanism in plants. The research results indicated that the transgenic lines could perform better under low-temperature stress by increasing the antioxidant enzyme activity and osmoregulatory substance content of the transgenic plants. CONCLUSIONS: This study provides genetic resources for analyzing the biological functions of PavHIPPs, which is important for elucidating the mechanisms of cold resistance in sweet cherry.


Assuntos
Nicotiana , Proteínas de Plantas , Plantas Geneticamente Modificadas , Prunus avium , Nicotiana/genética , Nicotiana/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Prunus avium/genética , Prunus avium/fisiologia , Prunus avium/metabolismo , Resposta ao Choque Frio/genética , Temperatura Baixa , Regulação da Expressão Gênica de Plantas
13.
BMC Plant Biol ; 24(1): 755, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39107750

RESUMO

BACKGROUND: Postharvest quality deterioration poses a significant challenge to the commercial value of fresh lotus seeds. Low temperature storage is widely employed as the primary method for preserving postharvest lotus seeds during storage and transportation. RESULTS: This approach effectively extends the storage life of lotus seeds, resulting in distinct physiological changes compared to room temperature storage, including a notable reduction in starch, protein, H2O2, and MDA content. Here, we conducted RNA-sequencing to generate global transcriptome profiles of postharvest lotus seeds stored under room or low temperature conditions. Principal component analysis (PCA) revealed that gene expression in postharvest lotus seeds demonstrated less variability during low temperature storage in comparison to room temperature storage. A total of 14,547 differentially expressed genes (DEGs) associated with various biological processes such as starch and sucrose metabolism, energy metabolism, and plant hormone signaling response were identified. Notably, the expression levels of DEGs involved in ABA signaling were significantly suppressed in contrast to room temperature storage. Additionally, nine weighted gene co-expression network analysis (WGCNA)-based gene molecular modules were identified, providing insights into the co-expression relationship of genes during postharvest storage. CONCLUSION: Our findings illuminate transcriptional differences in postharvest lotus seeds between room and low temperature storage, offering crucial insights into the molecular mechanisms of low temperature preservation in lotus seeds.


Assuntos
Temperatura Baixa , Sementes , Transcriptoma , Sementes/genética , Lotus/genética , Lotus/fisiologia , Lotus/metabolismo , Regulação da Expressão Gênica de Plantas , Perfilação da Expressão Gênica
14.
Small ; : e2309286, 2024 Mar 07.
Artigo em Catalão | MEDLINE | ID: mdl-38453682

RESUMO

As one of the key components of supercapacitors, electrolyte is intensively investigated to promote the fast development of the energy supply system under extremely cold conditions. However, high freezing point and sluggish ion transport kinetics for routine electrolytes hinder the application of supercapacitors at low temperatures. Resultantly, the liquid electrolyte should be oriented to reduce the freezing point, accompanied by other superior characteristics, such as large ionic conductivity, low viscosity and outstanding chemical stability. In this review, the intrinsically physical parameters and microscopic structure of low-temperature electrolytes are discussed thoroughly, then the previously reported strategies that are used to address the associated issues are summarized subsequently from the aspects of aqueous and non-aqueous electrolytes (organic electrolyte and ionic liquid electrolyte). In addition, some advanced spectroscopy techniques and theoretical simulation to better decouple the solvation structure of electrolytes and reveal the link between the key physical parameters and microscopic structure are briefly presented. Finally, the further improvement direction is put forward to provide a reference and guidance for the follow-up research.

15.
Small ; 20(22): e2309900, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38312091

RESUMO

All-hydrogel supercapacitors are emerging as promising power sources for next-generation wearable electronics due to their intrinsic mechanical flexibility, eco-friendliness, and enhanced safety. However, the insufficient interfacial adhesion between the electrode and electrolyte and the frozen hydrogel matrices at subzero temperatures largely limit the practical applications of all-hydrogel supercapacitors. Here, an all-hydrogel supercapacitor is reported with robust interfacial contact and anti-freezing property, fabricated by in situ polymerizing hydrogel electrolyte onto hydrogel electrodes. The robust interfacial adhesion is developed by the synergistic effect of a tough hydrogel matrix and topological entanglements. Meanwhile, the incorporation of zinc chloride (ZnCl2) in the hydrogel electrolyte prevents the freezing of water solvents and endows the all-hydrogel supercapacitor with mechanical flexibility and fatigue resistance across a wide temperature range of 20 °C to -60 °C. Such all-hydrogel supercapacitor demonstrates satisfactory low-temperature electrochemical performance, delivering a high energy density of 11 mWh cm-2 and excellent cycling stability with a capacitance retention of 90% over 10000 cycles at -40 °C. Notably, the fabricated all-hydrogel supercapacitor can endure dynamic deformations and operate well under 2000 tension cycles even at -40 °C, without experiencing delamination and electrochemical failure. This work offers a promising strategy for flexible energy storage devices with low-temperature adaptability.

16.
Small ; 20(1): e2303836, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37670221

RESUMO

The battery performance declines significantly in severely cold areas, especially discharge capacity and cycle life, which is the most significant pain point for new energy consumers. To address this issue and improve the low-temperature characteristic of aluminum-ion batteries, in this work, polydopamine-derived N-doped carbon nanospheres are utilized to modify the most promising graphite material. More active sites are introduced into graphite, more ion transport channels are provided, and improved ionic conductivity is achieved in a low-temperature environment. Due to the synergistic effect of the three factors, the ion diffusion resistance is significantly reduced and the diffusion coefficient of aluminum complex ions in the active material become larger at low temperatures. Therefore, the battery delivers an improved capacity retention rate from 23% to 60% at -20 °C and excellent ultra-long cycling stability over 5500 cycles at -10 °C. This provides a novel strategy for constructing low-temperature aluminum-ion batteries with high energy density, which is conducive to promoting the practicality of aluminum-ion batteries.

17.
Small ; : e2402245, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38747006

RESUMO

This study explores trivalent Al interaction with aqueous starch gel in the presence of two different anions through salting effect. Salting-out nature of Al2(SO4)3·18H2O with starch gel causes precipitation of starch; this happens due to competitive anion-water complex formation over starch-water interaction, thereby reducing polymer solubility. Salting-in effect of AlCl3 with starch gel happens through Al3+ cation interaction with hydroxyl group of starch and increases polymer solubility, making gel electrolyte viable for battery applications. Prepared gel electrolyte exhibits ionic conductivity of 1.59 mS cm-1 and a high tAl 3+ value of 0.77. The gel electrolyte's performance is studied using two different cathodes, the Al|MoO3 cell employing starch gel electrolyte achieves discharge capacity of 193 mA h g-1 and Al|MnO2 cell achieves discharge capacity of 140 mA h g-1 @0.1 A g-1 for first cycle. The diffusion coefficient of both cells using starch gel electrolyte is calculated and found to be 2.1 × 10-11 cm2 s-1 for Al|MoO3 and 3.1 × 10-11 cm2 s-1 for Al|MnO2 cells. The Al|MoO3 cell at lower temperature shows improved electrochemical performance with a specific capacity retention of ≈87.8% over 90 cycles. This kind of aqueous gel electrolyte operating at low temperature broadens the application for next generation sustainable batteries.

18.
Small ; : e2402608, 2024 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-38853133

RESUMO

The atomic/molecular layer deposition (ALD/MLD) technique combining both inorganic and organic precursors is strongly emerging as a unique tool to design exciting new functional metal-organic thin-film materials. Here, this method is demonstrated to work even at low deposition temperatures and can produce highly stable and conformal thin films, fulfilling the indispensable prerequisites of today's 3D microelectronics and other potential industrial applications. This new ALD/MLD process is developed for Zn-organic thin films grown from non-pyrophoric bis-3-(N,N-dimethylamino)propyl zinc [Zn(DMP)2] and 1,4-benzene dithiol (BDT) precursors. This process yields air-stable Zn-BDT films with appreciably high growth per cycle (GPC) of 4.5 Å at 60 °C. The Zn/S ratio is determined at 0.5 with Rutherford backscattering spectrometry (RBS), in line with the anticipated (Zn─S─C6H6─S─)n bonding scheme. The high degree of conformality is shown using lateral high-aspect-ratio (LHAR) test substrates; scanning electron microscopy (SEM) analysis shows that the film penetration depth (PD) into the LHAR structure with cavity height of 500 nm is over 200 µm (i.e., aspect-ratio of 400). It is anticipated that the electrically insulating metal-organic Zn-BDT thin films grown via the solvent-free ALD/MLD technique, can be excellent barrier layers for temperature-sensitive and flexible electronic devices.

19.
Small ; 20(21): e2306865, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38126669

RESUMO

Functional inks enable manufacturing of flexible electronic devices by means of printing technology. Silver nanoparticle (Ag NP) ink is widely used for printing conductive components. A sintering process is required to obtain sufficient conductivity. Thermal sintering is the most commonly used method, but the heat must be carefully applied to avoid damaging low-temperature substrates such as polymer films. In this work, two alternative sintering methods, damp heat sintering and water sintering are systematically investigated for inkjet-printed Ag tracks on polymer substrates. Both methods allow sintering polyvinyl pyrrolidone (PVP) capped Ag NPs at 85°C. In this way, the resistance is significantly reduced to only 1.7 times that of the samples on polyimide sintered in an oven at 250°C. The microstructure of sintered Ag NPs is analyzed. Taking the states of the capping layer under different conditions into account, the explanation of the sintering mechanism of Ag NPs at low temperatures is presented. Overall, both damp heat sintering and water sintering are viable options for achieving high conductivity of printed Ag tracks. They can broaden the range of substrates available for flexible electronic device fabrication while mitigating substrate damage risks. The choice between them depends on the specific application and the substrate used.

20.
Small ; 20(22): e2309181, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38100297

RESUMO

The development of catalysts with abundant active interfaces for superior low-temperature catalytic CO oxidation is critical to meet increasingly rigorous emission requirements, yet still challenging. Herein, this work reports a PtCo/CoOx/Al2O3 catalyst with PtCo clusters and enriched Pt─O─Co interfaces induced by hydrogen spillover from the Pt sites and self-oxidation process in air, exhibiting excellent performance for CO oxidation at low temperatures and humid conditions. The combination of structural characterizations and in situ Fourier transform infrared spectroscopy reveals that the PtCo cluster effectively prevents CO saturation/poisoning on the Pt surface. Additionally, the presence of Pt─O─Co interfaces in the PtCo/CoOx/Al2O3 catalyst provides a significant number of active sites for oxygen activation and ─OH formation. This facilitates efficient generation of CO2 at ambient temperature by coupling with nearby adsorbed CO molecules, resulting in superior low-temperature activity and long-term stability for CO oxidation under humid conditions. This work provides a facile route toward rationalizing the design of catalysts with more active interfaces for superior low-temperature CO oxidation under humid conditions for practical applications.

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