The urgent prerequisites of high energy‐density and superior electrochemical properties have been the main inspiration for the advancement of cathode materials in lithium‐ion batteries (LIBs) in the ...last two decades. Nickel‐rich layered transition‐metal oxides with large reversible capacity as well as high operating voltage are considered as the most promising candidate for next‐generation LIBs. Nonetheless, the poor long‐term cycle‐life and inferior thermal stability have limited their broadly practical applications. In the research of LIBs, it is observed that surface/interfacial structure and chemistry play significant roles in the performance of cathode cycling. This is due to the fact that they are basically responsible for the reversibility of Li+ intercalation/deintercalation chemistries while dictating the kinetics of the general cell reactions. In this Review, the surface/interfacial structure and chemistry of nickel‐rich layered cathodes involving structural defects, redox mechanisms, structural evolutions, side‐reactions among others are initially demonstrated. Recent advancements in stabilizing the surface/interfacial structure and chemistry of nickel‐rich cathodes by surface modification, core–shell/concentration‐gradient structure, foreign‐ion substitution, hybrid surface, and electrolyte additive are presented. Then lastly, the remaining challenges such as the fundamental studies and commercialized applications, as well as the future research directions are discussed.
The surface/interfacial structure and chemistry of nickel‐rich cathodes involving structural defects, redox mechanisms, structural evolutions, side‐reactions, etc., are initially presented. Recent advances in stabilizing its surface/interfacial structure and chemistry by surface modification, core−shell/concentration‐gradient structure, foreign‐ion substitution, hybrid surface and electrolyte additive are summarized. Finally, the remaining challenges including fundamental studies and commercialized applications, and future research directions are also discussed.
Photocatalytic hydrogen evolution has broad prospects as a clean solution for the energy crisis. However, the rational design of catalyst complex, the H2 evolution efficiency, and the yield are great ...challenge. Herein, three-dimensional hierarchical g-C3N4 architectures assembled by ultrathin carbon-rich nanosheets (3D CCNS) were prepared via an extremely facile hexamethylenetetramine activation approach at the bulk scale, indicating the validation of scale-up production process. The two-dimensional ultrathin carbon-rich nanosheets were several hundred nanometers in width but only 5–6 nm in thickness and gave rise to a unique 3D interconnected network. The unique composition and structure of the nanosheets endow them with a remarkable light absorption spectrum with the tunable band gap, high electrical conductivity, fast charge separation, and large surface areas with abundant reaction active sites, and thus significantly improved H2 production performance. As high as ∼7.8%, quantum efficiency can be achieved by irradiating 3D CCNS at 420 nm with a H2 evolution rate >2.7 × 104 μmol/g/h, which is ∼31.3 times higher than that of the pristine g-C3N4. Our work introduces an extremely facile route for mass production of doping modified 3D g-C3N4-based photocatalyst with excellent H2 evolution performances.
Hierarchically porous polypyrrole nanowires/manganese oxides nanoflakes (MnO2 NFs@PPy NWs) core/shell nanostructures were successfully constructed through a simple, convenient and environmentally ...friendly method by using PPy nanowires as the core buffer and K-Birnessite type MnO2 as the shell. The core/shell nanostructures effectively increase active surface areas and decrease the ion transmission distance, which is conducive to the efficient transfer of ions. The MnO2 NFs@PPy NWs core/shell nanostructures exhibited not only high specific capacitance (276Fg−1 at 2Ag−1) but also excellent capacitance retained ratio of 72.5% under extreme charge/discharge conditions (200Fg−1 at 20Ag−1) due to the synergistic effect by combining the merits of MnO2 and PPy. Using such hierarchical nanostructure as the positive electrode, we further demonstrate that ultra-flexible asymmetrical supercapacitors (AFSCs) (MnO2@PPy//AC) possess excellent cycling stability (90.3% after 6000 cycles at 3Ag −1), mechanical flexibility, large voltage operation window (1.8–2.0V vs. SCE) and high energy densities at all charge/discharge conditions (25.8Whkg−1 at the power density of 901.7Wkg−1, and 17.1Whkg−1 at the power density of 9000Wkg−1, respectively).
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•MnO2 nanoflakes@PPy nanowire core/shell nanoarchitectures were designed and synthesized.•Synergetic effects of MnO2 shell and PPy core are responsible for the high power density.•Ultra-flexible and high energy density asymmetrical supercapacitors were achieved.
Lead (Pb) and polycyclic aromatic hydrocarbon (PAH) exposure is positively associated with cardiovascular disease (CVD), and the possible potential mechanism may be caused by damage to the ...endothelium by modulation of inflammatory processes. No comprehensive research shows co-exposure of Pb and PAH on cardiovascular endothelial inflammation in electronic waste (e-waste) exposed populations. Given this, the aim of this study is to provide evidence for a relationship between Pb and PAH co-exposure and cardiovascular endothelial inflammation, in an e-waste-exposed population, to delineate the link between a potential mechanism for CVD and environmental exposure. We recruited 203 preschool children (3–7 years) were enrolled from Guiyu (e-waste-exposed group, n = 105) and Haojiang (reference group, n = 98). Blood Pb levels and urinary PAH metabolites were measured. Percentages of T cells, CD4+ T cells and CD8+ T cells, complete blood counts, endothelial inflammation biomarker (serum S100A8/A9), and other inflammatory biomarkers serum interleukin (IL)-6, IL-12p70, gamma interferon-inducible protein 10 (IP-10) levels were evaluated. Blood Pb, total urinary hydroxylated PAH (ΣOHPAH), total hydroxynaphthalene (ΣOHNap) and total hydroxyfluorene (ΣOHFlu) levels, S100A8/A9, IL-6, IL-12p70 and IP-10 concentrations, absolute counts of monocytes, neutrophils, and leukocytes, as well as CD4+ T cell percentages were significantly higher in exposed children. Elevated blood Pb, urinary 2-hydroxynaphthalene (2-OHNap) and ΣOHFlu levels were associated with higher levels of IL-6, IL-12p70, IP-10, CD4+ T cell percentages, neutrophil and monocyte counts. Mediator models indicated that neutrophils exert the significant mediation effect on the relationship between blood Pb levels and S100A8/A9. IL-6 exerts a significant mediation effect on the relationship between blood Pb levels and IP-10, as well as the relationship between urinary ΣOHFlu levels and IP-10. Our results indicate that children with elevated exposure levels of Pb and PAHs have exacerbated vascular endothelial inflammation, which may indicate future CVD risk in e-waste recycling areas.
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•Pb and PAH toxicity impair inflammatory cells and vascular endothelium.•Children from e-waste areas exhibit higher blood Pb and urinary PAH levels.•Blood Pb and urinary PAH levels positively correlate with inflammatory biomarkers.•Inflammatory biomarker levels may indicate future cardiovascular disease risk.
E-waste-exposed children have elevated levels of inflammatory biomarkers associated with increased blood Pb levels and urinary PAH metabolites, which may indicate future cardiovascular disease risk.
Lead (Pb) exposure and heart failure risk Chen, Zihan; Huo, Xia; Chen, Guangcan ...
Environmental science and pollution research international,
06/2021, Letnik:
28, Številka:
23
Journal Article
Recenzirano
Lead (Pb) is a heavy metal with widespread industrial use, but it is also a widespread environmental contaminant with serious toxicological consequences to many species. Pb exposure adversely impacts ...the cardiovascular system in humans, leading to cardiac dysfunction, but its effects on heart failure risk remain poorly elucidated. To better understand the pathophysiological effects of Pb, we review potential mechanisms by which Pb exposure leads to cardiac dysfunction. Adverse effects of Pb exposure on cardiac function include heart failure risk, pressure overload, arrhythmia, myocardial ischemia, and cardiotoxicity. The data reviewed clearly establish that Pb exposure can play an important role in the occurrence and development of heart failure. Future epidemiological and mechanistic studies should be developed to better understand the involvement of Pb exposure in heart failure.
Here, we will introduce the progress of g-C3N4 photocatalysts in hydrogen production from the aspects of changing the ratio of C and N, morphology, element doping and constructing heterostructures. ...Discuss the excellent results of various types of photocatalysts.
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g-C3N4 have been widely used in the fields of photocatalytic hydrogen production, photocatalytic degradation of dyes and oxidative degradation of toxic gases due to their excellent performance. It has attracted extensive attention in recent years due to its highly efficient photocatalytic capacity of hydrogen generation, water oxidation, carbon dioxide reduction and degradation of organic pollutants. Because of the abundant carbon and nitrogen composition of the earth, large-scale production and industrial applications of this material are possible. The modification of this material makes its performance more excellent so that this new material can obtain a steady stream of vitality. These outstanding works have become important materials and milestones on the road to mankind’s photocatalytic hydrogen production. This review will begin with the basic idea of designing, synthesizing and improving g-C3N4 based photocatalytic materials, and introduce the latest development of g-C3N4 photocatalysts in hydrogen production from four aspects of controlling the carbon/nitrogen ratio, morphology, element doping and heterojunction structure of g-C3N4 materials.
Nickel cobalt sulfides （Ni-Co-S） have attracted extensive attention for application in electronic devices owing to their excellent conductivity and high electrochemical capacitance. To facilitate the ...large-scale practical application of Ni-Co-S, the excellent rate capability and cyclic stability of these compounds must be fully exploited. Thus, hierarchical Ni-Co-S@Ni-W-O （Ni-Co-S-W） core/shell hybrid nanosheet arrays on nickel foam were designed and synthesized herein via a facile three-step hydrothermal method, followed by annealing in a tubular furnace under argon atmosphere. The hybrid structure was directly assembled as a free-standing electrode, which exhibited a high specific capacitance of 1,988 F·g^-1 at 2 A·g^-1 and retained an excellent capacitance of approximately 1,500 F·g^-1 at 30 A·g^-1, which is superior to the performance of the pristine Ni-Co-S nanosheet electrode. The assembled asymmetric supercapacitors achieved high specific capacitance （155 F·g^-1 at 1 A·g^-1）, electrochemical stability, and a high energy density of 55.1 W·h·kg^-1 at a power density of 799.8 W·kg^-1 with the optimized Ni-Co-S-W core/shell nanosheets as the positive electrode, activated carbon as the negative electrode, and 6 M KOH as the electrolyte.
To effectively avoid the “dead volume” and improve the utilization ratio of the electrode material, a novel longan-like hybrid structure has been designed and fabricated by controlled growth of ...Ni(OH)2 nanosheets on the surface of yolk–shell PPy nanospheres at a mild reaction temperature. The strategy takes full advantages of the hollow structure and further reduces the charge transport distance, leading to high conductivity and energy storage capacity of longan-like hybrid structures. Furthermore, the assembled asymmetric supercapacitors (ASCs) exhibits a high retention ratio of 91.5% for capacitance after 6000 continuous cycles and an impressive energy density of 34 W h kg−1 at 755 W kg−1. Remarkably, two devices in series have a higher cell-voltage output of 3.0 V compared to a single device. This work will supply a new hollow nanostructure design strategy to enhance the electrochemical performance of electrode materials.
A novel longan-like hybrid architecture takes full advantages of the hollow structure and further reduces the charge transport distance. Herein, a high conductivity and energy storage capacity can be achieved. Display omitted
•An interesting one-step process to synthesize bulk quantities yolk–shell polypyrrole nanospheres.•A novel longan–like hybrid structures been fabricated by controlled growth of Ni(OH)2 nanosheets on the surface of yolk–shell PPy nanospheres.•The hybrid structures not only reserves the advantages of hollow structures but also reduces charge transport distance, herein, a high conductivity and energy storage capacity can be reached.•The assembled ASCs display excellent electrochemical energy storage properties, and two devices in serial have a high output cell voltage.
We briefly summarize the fundamental mechanism of supercapacitors and classify them into three kinds according to the different energy storage mechanism. We further discuss the energy storage ...mechanism of nickel/cobalt based materials, and we suggest that these kinds of battery-type materials should be classified into hybrid supercapacitor instead of pseudocapacitors.
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The electrode materials as the key component of supercapacitors have attracted considerable research interests, especially for nickel/cobalt based materials by virtue of their superior electrochemical performance with multiple oxidation states for richer redox reactions, abundant natural resources, lower prices and toxicity. There are many advanced electrodes based on the nickel/cobalt materials exploited for the application of supercapacitors, however, some controversial statements have induced some confusion. Herein, we refine the mechanism of energy storage for the nickel/cobalt based materials for supercapacitors and reclassify them into battery-type materials with the corresponding devices named as hybrid supercapacitors.
One-dimensional (1D) metal-oxide nanostructures are ideal systems for exploring a large number of novel phenomena at the nanoscale and investigating size and dimensionality dependence of ...nanostructure properties for potential applications. The construction and integration of photodetectors or optical switches based on such nanostructures with tailored geometries have rapidly advanced in recent years. Active 1D nanostructure photodetector elements can be configured either as resistors whose conductions are altered by a charge-transfer process or as field-effect transistors (FET) whose properties can be controlled by applying appropriate potentials onto the gates. Functionalizing the structure surfaces offers another avenue for expanding the sensor capabilities. This article provides a comprehensive review on the state-of-the-art research activities in the photodetector field. It mainly focuses on the metal oxide 1D nanostructures such as ZnO, SnO(2), Cu(2)O, Ga(2)O(3), Fe(2)O(3), In(2)O(3), CdO, CeO(2), and their photoresponses. The review begins with a survey of quasi 1D metal-oxide semiconductor nanostructures and the photodetector principle, then shows the recent progresses on several kinds of important metal-oxide nanostructures and their photoresponses and briefly presents some additional prospective metal-oxide 1D nanomaterials. Finally, the review is concluded with some perspectives and outlook on the future developments in this area.
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