Designing and preparing polyaniline (PANI)-based flexible electrode materials with special nanostructure hold critical promise as capacitive materials. Here, the PANIs were synthesized in HCl, H2SO4, ...phytic acid and HPF6 reaction systems with the same concentration via fast microwave-assisted chemical polymerization. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, UV-vis absorption spectroscopy, and X-ray photoelectron spectroscopy (XPS) were conducted to characterize their nanostructures and chemical compositions. Results reveal an apparent influence of acidic types on PANI morphology and nanostructures. The HPF6-doped PANI/carbon cloth (F-PANI/CC) show the morphology of 3D honeycomb-like nanosheets and highly ordered phenazine-like oligomeric structure as well as higher homogeneous protonation of PANI backbones on the substrate of carbon cloth (CC). These main features favor the formation of rich electron centers, density of electric charges, and better contact and reaction between PANI materials and electrolyte. As a consequence, the assembled F-PANI/CC-based symmetric solid-state supercapacitor exhibits favorable electrochemical performance with a maximum energy density of 32.6 Wh kg−1 and a maximum power density of 1693 W kg−1 at a voltage window of 1.0 V compared with other PANI electrode materials. This work would inspire the HPF6-doped PANI electrode materials for high-performance flexible supercapacitors.
The flexible F-PANI/CC electrode has 3D honeycomb-like nanosheets and highly ordered phenazine-like oligomeric structure as well as higher homogeneous protonation of PANI backbones, which exhibits favorable electrochemical performance in flexible supercapacitors Display omitted
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Ag nanobelts with the special structure and surface of raised Ag mounds and superlattice fringes were prepared via redox replacement reaction, which are revealed to have improved electrical ...conductivity and electrochemical performance in both Zn-Ag and Zn-Ag/air hybrid battery.
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•The silver nanobelts were prepared by redox replacement reaction.•A special structure feature was obtained on the Ag NBs surface.•The assembled Zn-Ag/air battery exhibits favorable electrochemical performance.•A potential application of Ag NBs was revealed in hybrid Zn-Ag/air batteries.
The Zn-Ag and Zn-Ag/air hybrid batteries are challenged by the low conductivity and capacity of Ag electrode materials. How to further optimize and tune the surface electronic structure of Ag nanomaterials has become an important topic in the improvement of Ag electrode materials. Herein, the silver nanobelts (Ag NBs) materials were prepared by a fast and simple redox replacement reaction. The special nanobelts structure, with the key surface features of the gully-like morphology, raised Ag mounds and superlattice fringes, are beneficial to tune the surface electron structure and thereby increase the conductivity and electrochemical performance of Ag NBs. As a consequence, the assembled Zn-Ag battery exhibits favorable electrochemical performance in view of the specific capacity of 380.9 mAh gAg−1. In addition, the hybrid Zn-Ag/air battery shows two-step voltage plateaus of 1.83 and 1.55 V in the Zn-Ag reaction, as well as a voltage plateau of 1.23 V corresponding to the Zn-air reaction. The hybrid battery maintains a high energy efficiency of 76.9% and high rate capabilities, demonstrating an excellent energy-saving feature of this battery. The insights gained from this work may be beneficial for designing the highly-efficient Ag catalysts for electrochemical energy storage.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Fiber supercapacitors (FSCs) are promising energy storage devices in portable and wearable smart electronics. Currently, a major challenge for FSCs is simultaneously achieving high volumetric energy ...and power densities. Herein, the microscale fiber electrode is designed by using carbon fibers as substrates and capillary channels as microreactors to space‐confined hydrothermal assembling. As P‐doped graphene oxide/carbon fiber (PGO/CF) and NiCo2O4‐based graphene oxide/carbon fiber (NCGO/CF) electrodes are successfully prepared, their unique hybrid structures exhibit a satisfactory electrochemical performance. An all‐solid‐state PGO/CF//NCGO/CF flexible asymmetric fiber supercapacitor (AFSC) based on the PGO/CF as the negative electrode, NCGO/CF hybrid electrode as the positive electrode, and poly(vinyl alcohol)/potassium hydroxide as the electrolyte is successfully assembled. The AFSC device delivers a higher volumetric energy density of 36.77 mW h cm−3 at a power density of 142.5 mW cm−3. In addition, a double reference electrode system is adopted to analyze and reduce the IR drop, as well as effectively matching negative and positive electrodes, which is conducive for the optimization and improvement of energy density. For the AFSC device, its better flexibility and electrochemical properties create a promising potential for high‐performance micro‐supercapacitors. Furthermore, the introduction of the double reference electrode system provides an interesting method for the study on the electrochemical performances of two‐electrode systems.
An all‐solid‐state P‐doped graphene oxide/carbon fiber (PGO/CF)//NiCo2O4‐based graphene oxide/carbon fiber (NCGO/CF) flexible asymmetric fiber supercapacitor (AFSC) with favorable flexibility and electrochemical properties is successfully assembled based on the PGO/CF and NCGO/CF electrodes. Interestingly, the introduction of the double reference electrode system provides a promising method for the study of the electrochemical performances of two‐electrode systems.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The increase of (100) and (110) planes and surface oxygen species promotes reduction property of the aged CeO2-ZrO2 catalysts but cannot do soot-O2 reaction activity.
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•Soot oxidation ...activity would not depend on the reduction ability.•The changes in reducibility of the aged CeZrO2 depend on Ce/Zr ratio.•Ce0.27Zr0.73O2 shows increased surface oxygen species and O-vacancies after aging.•Increase of (100) and (110) planes promotes reduction ability.•Soot oxidation activity is mainly determined by structural and textural properties.
CexZr(1-x)O2 (x = 0.27, 0.50 and 0.73) mixed oxides were prepared by co-precipitation method and then aged at 700–1000 °C. The reducibility of the aged catalysts was investigated by H2-TPR. It was found that the changes in reduction properties are related to the Ce/Zr ratio and Ce0.27Zr0.73O2 shows an increased H2 consumption with aging temperature increasing, even 1000 °C-aged samples show an increased reduction ability. Raman, XPS and HRTEM reveal that the promotion on reduction property of the aged samples should be ascribed to the increase of surface oxygen species, surface Ce/Zr ratio, O-vacancies and (110) and (100) planes. However, this promotion can not obviously improve soot oxidation activity. XRD, BET and O2-TPD results reveal that textural, structural and oxygen desorption properties are crucial to soot oxidation activity. The poor contact between soot and active sites would be an important factor that leads to a contradiction between H2-TPR and soot-O2 reaction activity.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
As potential catalytic materials for the oxygen evolution reaction, abundant and eco-friendly iron-based materials are often limited by inferior electrical conductivity. Herein, we propose a ...cost-effective and facile strategy to prepare a Fe/C heterostructured composite (Fe/Fe 3 C–F@CNT) via ultra-fast pyrolysis of ferrocene based on the induction and microwave thermal effect of multiwalled carbon nanotubes (CNTs). Fe/Fe 3 C–F@CNT exhibits a novel heterostructure where carbon-encapsulated Fe/Fe 3 C nanoparticles are uniformly distributed on the surface of CNTs and small iron-based nano-clusters exist on the surface of carbon layer, thus improving the electrical conductivity and dispersion of active sites. Fe/Fe 3 C–F@CNT shows superior OER catalytic performance, which is better than that of many Co- and Ni-based catalysts and even superior to that of RuO 2 . Furthermore, the catalytic performance further improved by loading Fe/Fe 3 C–F@CNT on the commercial foam iron. The resultant composite required a low overpotential (286 mV) to reach the current density of 10 mA cm −2 . The durable catalytic stability, exhibiting no significant degradation at 100 mA cm −2 after 320 h, makes Fe/Fe 3 C–F@CNT a promising efficient, low-cost and environmentally-friendly OER catalyst for application in water electrolysis and metal–air batteries. More importantly, this study greatly shortens the preparation time required to fabricate uniform Fe/C heterostructures. This study brings a new inspiration for fabricating various materials for application as green energy sources.
The low-cost fabrication of large-area hierarchical micro- and nanostructures is critical for the practical applications of superhydrophobic metallic surfaces. Instead of using ultrafast lasers, ...low-cost near-infrared nanosecond (ns) lasers were used in this study to induce the formation of hierarchical micro- and nanostructures on copper surfaces. We found that the ns laser-treated surfaces with medium-height microstructures densely covered by nanoparticles demonstrated stable superhydrophobicity, lower water adhesion and superior frost resistance. In the experiment, the micro- and nanostructures induced by treatment with ns lasers with a pulse width of 100 ns showed better performance in term of superhydrophobicity, water adhesion and frost resistance. However, the obtained structures were sensitive to the laser pulse energy when long pulse widths were used. The advantage of short laser pulses was that, hierarchical micro- and nanostructures with good performance could still be obtained with low laser energy. Our findings prove that low-cost ns lasers are also suitable for the fabrication of metallic superhydrophobic surfaces and that different applicable laser parameters are needed when the laser pulse width varies.
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•Ns laser-induced microstructures with a medium height densely covered by nanoparticles showed better performances.•The morphology of the surface structures induced by long laser pulses was more sensitive to the laser pulse energy.•Surfaces with good superhydrophobicity performance can be obtained with low laser energy when using short laser pulses.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The hepatic vascular niche plays an important role in the pathological process of liver fibrosis. Liver sinusoidal endothelial cells (LSECs) predominantly compose hepatic vascular niches. Endothelial ...cell (EC)‐expressing sphingosine 1‐phosphate receptor 2 (S1pr2) plays an essential role in the regulation of vascular functions. Nevertheless, it remains unknown whether liver LSEC‐S1pr2 might modulate pathological liver fibrosis. In this study, liver fibrosis was induced by hepatotoxin carbon tetrachloride (CCl4). The expression of S1pr2 is significantly downregulated in liver sinusoidal endothelial cells after CCl4 treatment. The loss of S1pr2 in LSECs significantly alleviated liver fibrosis after chronic insult, whereas the overexpression of S1pr2 in LSECs accentuated liver fibrogenesis. In vivo experiments further revealed that the deficiency of S1pr2 in LSECs dampened hepatic stellate cell (HSC) activation, while overexpression of S1pr2 in LSECs enhanced HSC activation with more extracellular matrix component production. Mechanistically, LSEC‐S1pr2 activates the YAP signaling pathway to potentiate the transactivation of TGF‐β, which acts on HSCs in a paracrine manner, and thus aggravated liver fibrosis. Taken together, our results uncover a novel pathological mechanism of liver fibrosis in which LSEC‐S1pr2 plays an important role in modulating the development of liver fibrosis, providing a future novel therapy target against liver fibrogenesis.
Liver sinusoidal endothelial cells play pivotal roles in liver function and influences the development of liver fibrosis. This study revealed the molecular mechanism by which liver sinusoidal endothelial cells tightly controlled liver fibrosis progression. That is, liver sinusoidal endothelial cells express an important receptor, sphingosine 1‐ phosphate receptor 2 (S1pr2), which activates the Yap signaling pathway to upregulate the expression of TGF‐β, and thus influences the development of liver fibrosis. This finding provides a novel therapeutic target against liver fibrosis.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In this work, we report a new type anode material, MoO2 combined carbon dots (CDs) with nanoparticle-stacking structure via a facile hydrothermal route. Herein, CDs is introduced as the reductant ...which in-situ reduces MoVI to MoIV. It is further confirmed that the particles of MoO2 with evenly distributed beset of carbon dots form a nanoparticle-stacking structure. Thanks to this specific structure, the as-made MoO2-CDs manifest high performance in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). The capacities maintain 854 and 236 mAh g−1 at 0.50 A g−1 after 300 cycles for LIBs and 600 cycles for SIBs, respectively. Furthermore, we explored the structure-stability relationship by the electrochemical measurement and morphology, found the mechanisms of charge/discharge composed of dominant redox reaction and auxiliary intercalation reaction, and explained the characteristics of a high rate performance through kinetic issues and extrinsic pseudocapacitance contributions. This green synthetic method of anode material could make it possible to obtain high-performance alkali-ion batteries and other energy storage devices.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Cervical cancer (CC) is one of the most common cancers among women with high recurrence rates all over the world. Recently, the molecular mechanism of CC has been gradually uncovered in accumulating ...reports. This study aimed to investigate the function and upstream regulation mechanism of pyruvate dehydrogenase kinase 4 (PDK4) in CC cells, which was verified as an oncogene in several cancers. Through RT‐qPCR assay, we discovered that PDK4 was highly expressed in CC cells. Then, it was demonstrated in function assays that PDK4 facilitated CC cell proliferation and invasion, but inhibited CC cell apoptosis. Next, we sought to determine the upstream genes of PDK4, and miR‐103a‐3p was identified to target PDK4. Then, through bioinformatics tools and a range of mechanism assays, long intergenic non‐protein coding RNA 662 (LINC00662) was verified as the sponge of miR‐103a‐3p. Moreover, LINC00662 positively modulated PDK4 expression via competitively binding to miR‐103a‐3p in CC cells. Subsequently, rescue assays demonstrated that LINC00662 accelerated CC cell proliferation and inhibited cell apoptosis through upregulating PDK4. Furthermore, forkhead box A1 (FOXA1) was verified to activate transcription of both LINC00662 and PDK4. Taken together, our study revealed a novel ceRNA pattern of LINC00662/miR‐103a‐3p/PDK4 with FOXA1 as a transcription factor of LINC00662 and PDK4 in CC cells.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Fruit and vegetable fermented beverages, a functional non-dairy fermented product, are popular worldwide due to their health-promoting attributes. It is reported that a variety of nutrients and ...chemical composition are found in fruit and vegetable fermented beverages, and health-promoting effects also have been reported. In addition, the quality and consumer acceptance of products is largely affected by probiotics starter, fermentation process, juice sterilization process and beverage enhancements. Considering the extensive reports on fruit and vegetable fermented beverages, the summary of these aspects is rare and not comprehensive enough. In view of this, we realized that it is necessary to update influencing factors of the quality and consumer acceptance of fruit and vegetable fermented beverages and some of the technologies involved, as well as nutrients, chemical properties and health benefits. Based on recent developments, it can be anticipated that fruit and vegetable fermented beverages will continue to be an important part of the functional food market.
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