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1.
ChemSusChem ; : e202400997, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38923349

RESUMO

The design and construction of highly efficient electrocatalysts for overall water splitting and urea electrolysis are significantly important for promoting energy conversion and realizing green hydrogen production. In this work, we constructed a multi-phase heterojunction through a simple hydrothermal and phosphorization process. The P-doped NiFe2O4 (P-NiFe2O4) nanoparticles were uniformly anchored on the bamboo-like N-doped carbon nanotubes (NCNTs) grown via a NiFe-alloy autocatalysis. The electronic structure and coordination environment of active species were optimized by the synergistic action of P doping, well-dispersed ultrafine NiFe2O4, and NCNTs matrix with good conductivity, enhancing their quantity and activity for electrocatalysis. Consequently, the P-NiFe2O4/NCNTs/NiFe exhibits excellent HER and OER activities with an overpotential of 111 and 266 mV at 10 mA cm-2 in 1 M KOH, respectively. The symmetrical overall water-splitting cell using P-NiFe2O4/NCNTs/NiFe as both anode and cathode delivers 10 mA cm-2 at a voltage of 1.604 V in 1 M KOH. Notably, the two-electrode cell requires a low voltage of 1.467 V to achieve a current density of 10 mA cm-2 in 1 M KOH solution with 0.6 M urea. This designed catalysts display outstanding reaction kinetics and catalytic stability. This work provides useful guidance for applying transition metal-based catalysts for hydrogen production.

2.
J Colloid Interface Sci ; 672: 543-551, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38852355

RESUMO

Anode-free lithium metal batteries (AFLBs) have attracted considerable attention due to their high theoretical specific capacity and absence of Li. However, the heterogeneous Li deposition and stripping on the lithiophobic Cu collector hamper AFLBs in practice. To achieve a uniform and reversible Li deposition, a carbon-based layer on the Cu collector has attracted intense interest due to its high conductivity. However, the 2D single-component carbon-based interface is inadequate lithiophilic for obtaining the homogeneous Li deposition and preventing the lithium dendrite from piercing the separator. Herein, we present a 3D embedded lithiophilic SiO2 nanoparticles-graphene nanosheet matrix (SiO2@G-M) on the Cu collector by organic nano carbon source. In this structure, the lithiophilic SiO2 nanoparticles as active points promote the homogeneous lithium nucleation and the 3D graphene nanosheet matrix offers homogenous electron distribution and voids to prevent the piercing. Finally, SiO2@G-M/Li cell shows a high coulombic efficiency of 98.62 % after 100 cycles at a high current density of 2 mA cm-2 with an areal capacity of 1 mAh cm-2.

3.
ACS Appl Mater Interfaces ; 16(24): 31524-31533, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38841741

RESUMO

Metal-halide perovskite nanocrystals (NCs) are one of the most promising emitters for the application of display and nanolight sources. The full width at half-maximum (FWHM) of photoluminescence (PL) emission is essential for color purity, which however remains a difficulty to further reduce the FWHM of the perovskite NCs at room temperature. Here, we show the quasi-sphere perovskite NCs with narrow PL emission at a deep-blue wavelength of ∼430 nm; its PL FWHM reaches ∼11 nm at room temperature, owing to the monodispersion in size distribution as well as the symmetric quasi-sphere morphology of NCs releasing the fine structure splitting-induced inhomogeneous broadening. Through regulating A cations with respect to the ratio of FA (or MA)-to-Cs and Cs-to-Pb, the PL emission of the NCs could be tuned from ∼505 to ∼430 nm combined with varied morphologies from large cube to small quasi-sphere. Such spectroscopic and morphological discrepancies are supposed to be attributed to the different crystalline kinetics that is strongly dependent on the synthetic condition. To be specific, in the case of increasing FA (or MA)-to-Cs, the growth rate of CsPbBr3 and FAPbBr3 (or MAPbBr3) perovskites is determined by the reactivity of transient species, while in the case of decreasing the Cs-to-Pb ratio, the growth rate of perovskites is slowed down by the serious reduction of Cs+ in the precursor. This study provides an effective strategy to adjust the emission across from green to deep-blue color and promotes the perovskite NCs with a narrow FWHM, and tunable PL emission facilitates in application of optoelectronic devices.

4.
ACS Nano ; 18(4): 3791-3800, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38226921

RESUMO

The design and synthesis of efficient, inexpensive, and long-term stable heterostructured electrocatalysts with high-density dislocations for hydrogen evolution reaction in alkaline media and seawater are still a great challenge. An amorphous/crystalline/amorphous sandwiched structure with abundant dislocations were synthesized through thermal phosphidation strategies. The dislocations play an important role in the hydrogen evolution reactions. Copious dislocation defects, combined with cracks, and the synergistic interfacial effect between crystalline phase and amorphous phase regulate the electronic structure of electrocatalyst, provide more active sites, and thus endow the electrocatalysts with excellent catalytic activity under alkaline water and seawater. The overpotentials of P-NiMoO4 at 10 mA/cm2 in 1 M KOH aqueous solution and seawater are 45 and 75 mV, respectively. Additionally, the P-NiMoO4 electrocatalyst exhibits long-term stability over 100 h. This study provides a simple approach for synthesizing amorphous/crystalline/amorphous sandwiched non-noble-metal electrocatalysts with abundant dislocations for hydrogen evolution reaction.

5.
Artigo em Inglês | MEDLINE | ID: mdl-38019962

RESUMO

Lithium-sulfur (Li-S) batteries have ultrahigh theoretical specific capacity and energy density, which are considered to be very promising energy storage devices. However, the slow redox kinetics of polysulfides are the main reason for the rapid capacity decay of Li-S batteries. A reasonable electrocatalyst for the Li-S battery should reduce the reaction barrier and accelerate the reaction kinetics of the bidirectional catalytic conversion of lithium polysulfides (LiPSs), thereby reducing the cumulative concentration of LiPSs in the electrolyte. In this report, porous N-doped carbon nanofibers decorated with independent dual metal sites as catalysts for Li-S batteries were fabricated in one step using a fusion-foaming method. Experimental and theoretical analyses demonstrate that the synergistic effect of independent dual metal sites provides strong LiPS affinity, improved electronic conductivity, and enhanced redox kinetics of polysulfides. Therefore, the assembled Li-S battery exhibits high rate performance (discharge specific capacity of 771 mA h g-1 at 2C) and excellent cycle stability (capacity decay rate of 0.51% after 1000 cycles at 1C).

6.
Materials (Basel) ; 16(17)2023 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-37687423

RESUMO

Dye-sensitized solar cells (DSSCs) have emerged as a potential candidate for third-generation thin film solar energy conversion systems because of their outstanding optoelectronic properties, cost-effectiveness, environmental friendliness, and easy manufacturing process. The electron transport layer is one of the most essential components in DSSCs since it plays a crucial role in the device's greatest performance. Silver ions as a dopant have drawn attention in DSSC device applications because of their stability under ambient conditions, decreased charge recombination, increased efficient charge transfer, and optical, structural, and electrochemical properties. Because of these concepts, herein, we report the synthesis of pristine TiO2 using a novel green modified solvothermal simplistic method. Additionally, the prepared semiconductor nanomaterials, Ag-doped TiO2 with percentages of 1, 2, 3, and 4%, were used as photoanodes to enhance the device's performance. The obtained nanomaterials were characterized using XRD, FTIR, FE-SEM, EDS, and UV-vis techniques. The average crystallite size for pristine TiO2 and Ag-doped TiO2 with percentages of 1, 2, 3, and 4% was found to be 13 nm by using the highest intensity peaks in the XRD spectra. The Ag-doped TiO2 nanomaterials exhibited excellent photovoltaic activity as compared to pristine TiO2. The incorporation of Ag could assist in successful charge transport and minimize the charge recombination process. The DSSCs showed a Jsc of 8.336 mA/cm2, a Voc of 698 mV, and an FF of 0.422 with a power conversion efficiency (PCE) of 2.45% at a Ag concentration of 4% under illumination of 100 mW/cm2 power with N719 dye, indicating an important improvement when compared to 2% Ag-doped (PCE of 0.97%) and pristine TiO2 (PCE of 0.62%).

7.
J Colloid Interface Sci ; 651: 415-423, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37549526

RESUMO

Black phosphorus (BP), as a burgeoning two-dimensional material, has shown good electrocatalytic activity due to its unique electronic structure and abundant active sites.However, the presence of lone pair electrons in black phosphorus leads to its poor stability and rapid degradation in an oxygen/water environment, which greatly limits its practical application. Herein, BP-Co heterojunctions were synthesized on carbon nanotube@nitrogen-doped carbon (BP-Co/CNT@NC) by the pyrolysis of ZnCo-zeolitic imidazolate frameworks and subsequent solvothermal treatment. The BP-Co Schottky junction improved the electrocatalytic stability of BP, modulated its electronic structure, improved its conductivity and electron transfer during the electrocatalytic reaction. Density functional theory calculation was used to confirm the electron transfer and redistribution at the interface between BP and Co, which constructed an oppositely charged region and formed a strong built-in field. Energy band configuration analysis revealed a narrowed band gap because of the formation of BP-Co Schottky junction. Consequently, the optimized BP-Co/CNT@NC exhibited a superior oxygen evolution reaction (OER) performance, a low overpotential of 370 mV@100 mA/cm2, with a small Tafel slope of 40 mV/dec and good long-term stability. Particularly, the catalyst has an excellent OER performance at the high current density of 100-400 mA/cm2. This strategy improves the stability of BP electrocatalysts and strengthens their utilization in electrocatalytic applications.

8.
Biochim Biophys Acta Mol Basis Dis ; 1869(8): 166805, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37468019

RESUMO

Neoatherosclerosis (NA), the main pathological basis of late stent failure, is the main limitation of interventional therapy. However, the specific pathogenesis and treatment remain unclear. In vivo, NA model was established by carotid wire injury and high-fat feeding in ApoE-/- mice. Oxidized low-density lipoprotein receptor-1/lectin-like oxidized low-density lipoprotein receptor-1 (OLR1/LOX-1), a specific receptor for oxidized low-density lipoprotein (ox-LDL), was specifically ectopically overexpressed in hepatocytes by portal vein injection of adeno-associated serotype 8 (AAV8)-thyroid binding globulin (TBG)-Olr1 and the protective effect against NA was examined. In vitro, LOX-1 was overexpressed on HHL5 using lentivirus (LV)-OLR1 and the vascular smooth muscle cells (VSMCs)-HHL5 indirect co-culture system was established to examine its protective effect on VSMCs and the molecular mechanism. Functionally, we found that specific ectopic overexpression of LOX-1 by hepatocytes competitively engulfed and metabolized ox-LDL, alleviating its resulting phenotypic transformation of VSMCs including migration, downregulation of contractile shape markers (smooth muscle α-actin (SMαA) and smooth muscle-22α (SM22α)), and upregulation of proliferative/migratory shape markers (osteopontin (OPN) and Vimentin) as well as foaminess and apoptosis, thereby alleviating NA, which independent of low-density lipoprotein (LDL) lowering treatment (evolocumab, a monoclonal antibody to proprotein convertase subtilisin/kexin type 9 (PCSK9)). Mechanistically, we found that overexpression of LOX-1 in hepatocytes competitively engulfed and metabolized ox-LDL through upregulation of arachidonate-15-lipoxygenase (ALOX15), which further upregulated scavenger receptor class B type I (SRBI) and ATP-binding cassette transporter A1 (ABCA1). In conclusion, the overexpression of LOX-1 in liver protects VSMCs from phenotypic transformation and wire injury induced carotid neoatherosclerosis through ALOX15.


Assuntos
Músculo Liso Vascular , Pró-Proteína Convertase 9 , Animais , Camundongos , Araquidonato 15-Lipoxigenase/genética , Araquidonato 15-Lipoxigenase/metabolismo , Hepatócitos/metabolismo , Lipoproteínas LDL/metabolismo , Músculo Liso Vascular/metabolismo , Fenótipo , Receptores Depuradores Classe E/genética , Receptores Depuradores Classe E/metabolismo
9.
Angew Chem Int Ed Engl ; 62(39): e202304947, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37249158

RESUMO

Pursuing high power density lithium metal battery with high safety is essential for developing next-generation energy-storage devices, but uncontrollable electrolyte degradation and the consequence formed unstable solid-electrolyte interface (SEI) make the task really challenging. Herein, an ionic liquid (IL) confined MOF/Polymer 3D-porous membrane was constructed for boosting in situ electrochemical transformations of Janus-heterarchical LiF/Li3 N-rich SEI films on the nanofibers. Such a 3D-Janus SEI-incorporated into the separator offers fast Li+ transport routes, showing superior room-temperature ionic conductivity of 8.17×10-4  S cm-1 and Li+ transfer number of 0.82. The cryo-TEM was employed to visually monitor the in situ formed LiF and Li3 N nanocrystals in SEI and the deposition of Li dendrites, which is greatly benefit to the theoretical simulation and kinetic analysis of the structural evolution during the battery charge and discharge process. In particular, this membrane with high thermal stability and mechanical strength used in solid-state Li||LiFePO4 and Li||NCM-811 full cells and even in pouch cells showed enhanced rate-performance and ultra-long life spans.

10.
J Colloid Interface Sci ; 630(Pt A): 535-543, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36270174

RESUMO

Lithium-sulfur battery is one of the most promising candidates for next-generation energy storage systems, but the serious shuttle effect and sluggish reaction kinetics of polysulfides impair its practical applications. Herein, sulfur-deficient MoS2/carbon hollow nanospheres (MoS2-CHNs) are firstly synthesized by a NaCl-template pyrolysis and employed as sulfur host for lithium-sulfur batteries. TEM analysis reveals that carbon hollow nanospheres existing in the composite are the backbones that help to immobilize the ultrathin MoS2 nanosheets and ensure their large specific surface area. The MoS2 nanosheets consist of 5-10 layers of MoS2 with rich sulfur vacancies. The first principle calculation demonstrates that sulfur vacancy led to an intensively enhanced binding energy (-4.70 eV) towards Li2S6 compared to the pristine MoS2 (-1.57 eV). It suppressed the shuttle effect efficiently. The catalytic experiments reveal that MoS2-CHNs have a superior ability for the nucleation of Li2S and bidirectional electrocatalytic capability for the conversion of polysulfide. The large storage space inside MoS2-CHNs can work as a reservoir for intermediate polysulfides to substantially reduce the concentration overpotential. Due to this advantageous structural design of MoS2-CHNs electrode, its reversible capacity remains 1139 mAh g-1 after 100 cycles at 0.2C, and 600 mAh g-1 after 500 cycles at 5C with a sulfur loading of 5 mg cm-2. Even though the sulfur loading increases to 10 mg cm-2, the Li-S battery delivers a stable capacity of 978 mAh g-1 after 50 cycles at 0.2C. So the MoS2-CHNs demonstrate a promising application for high-energy Li-S batteries.


Assuntos
Carbono , Nanosferas , Molibdênio , Lítio , Enxofre
11.
Small ; 18(35): e2202779, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35934891

RESUMO

Transition metal nanostructures are widely regarded as important catalysts to replace the precious metal Pt for hydrogen evolution reaction (HER) in water splitting. However, it is difficult to obtain uniform-sized and ultrafine metal nanograins through general high-temperature reduction and sintering processes. Herein, a novel method of chemical energy-driven lithiation is introduced to synthesize transition metal nanostructures. By taking advantage of the slow crystallization kinetics at room temperature, more surface and boundary defects can be generated and remained, which reduce the atomic coordination number and tune the electronic structure and adsorption free energy of the metals. The obtained Ni nanostructures therein exhibit excellent HER performance. In addition, the bimetal of Co and Ni shows better electrocatalytic kinetics than individual Ni and Co nanostructures, reaching 100 mA cm-2 at a low overpotential of 127 mV. The high HER performance originates from well-formed synergistic effect between Ni and Co by tuning the electronic structures. Density functional theory simulations confirm that the bimetallic NiCo possesses a low Gibbs free energy of hydrogen adsorption, which are conducive to enhance its intrinsic activity. This work provides a general strategy that enables simultaneous defect engineering and electronic modulation of transition metal catalysts to achieve an enhancement in HER performance.

12.
Mol Med ; 28(1): 26, 2022 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-35236285

RESUMO

OBJECTIVE: Oxidized Low-Density-Lipoprotein (Ox-LDL) is the core factor in the development of atherosclerosis. However, there are few therapies aimed at eliminating Ox-LDL. Here in this study, we investigate whether the ectopically expression of the lectin-like oxidized low density lipoprotein receptor (LOX-1) in the liver could lead to the elimination of circulating Ox-LDL and prevent the deposition in the vascular wall, thereby alleviating the progression of atherosclerosis. METHODS: Apolipoprotein E-deficient (ApoE-/-) mice were randomly divided into three groups, the control group, the AAV8-TBG-eGFP group (eGFP group) and AAV8-TBG-LOX-1 group (LOX-1 group). In the LOX-1 group, mice received an injection of virus dilution AAV8-TBG-LOX-1 (1.16 × 1011 virus genome (v.g)/animal/100 µl). The mice in the control group and eGFP group received the same amount of sterile saline and AAV8-TBG-eGFP virus dilution injections. The expression of LOX-1 in the liver was detected by immunofluorescent, western blot and immunohistochemistry. The safety of the virus was assessed by hematoxylin-eosin (H&E) staining, blood biochemical analyses and immunofluorescent. The function of LOX-1 in the liver was detected by the co-localization of LOX-1 and Dil-labeled Ox-LDL (Dil-Ox-LDL) under laser scanning confocal microscope. The extent of Ox-LDL in plasma was detected by ELISA. Changes in blood lipids were assessed through blood biochemical analysis. The progression of atherosclerotic lesions was detected by Oil red O staining. And the expression of Vascular Cell Adhesion Molecule-1 (VCAM-1) in endothelial cells and the extent and migration of macrophages in atherosclerotic plaque were detected by immunofluorescence staining. The protein expression in liver was assessed by qRT-PCR and western blot. RESULTS: The expression of LOX-1 was stable in liver within 4 weeks. Ectopically expressed LOX-1 in the liver phagocytosed and degraded Ox-LDL and reduced Ox-LDL from circulation but did not have a significant effect on blood lipid levels. After the expression of LOX-1 in liver, Ox-LDL can be cleared by the hepatocytes, thereby reducing VCAM-1 expression in vascular endothelium and the migration of macrophages in plaques, and eventually alleviating the progression of atherosclerosis. Functional expression of LOX-1 in hepatocytes may facilitate the metabolic clearance of Ox-LDL by upregulating the expression of ATP-binding cassette G5 and G8 (ABCG5/G8), which is the primary neutral sterol transporter in hepatobiliary and transintestinal cholesterol excretion. CONCLUSION: Ectopic liver-specific expression of LOX-1 receptor alleviates the progression of atherosclerosis by clearing Ox-LDL from circulation.


Assuntos
Aterosclerose , Placa Aterosclerótica , Animais , Aterosclerose/metabolismo , Células Endoteliais/metabolismo , Lipídeos , Lipoproteínas LDL/metabolismo , Fígado/metabolismo , Camundongos , Placa Aterosclerótica/metabolismo , Placa Aterosclerótica/patologia , Receptores Depuradores Classe E/genética , Receptores Depuradores Classe E/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo
13.
ACS Appl Mater Interfaces ; 13(46): 55263-55271, 2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34756011

RESUMO

The exploration for low-cost bifunctional materials for highly efficient overall water splitting has drawn profound research attention. Here, we present a facile preparation of Mo-P dual-doped Co/oxygen-deficient Co3O4 core-shell nanorods as a highly efficient electrocatalyst. In this strategy, oxygen vacancies are first generated in Co3O4 nanorods by lithium reduction at room temperature, which endows the materials with bifunctional characteristics of the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). A Co layer doped with Mo and P is further deposited on the surface of the Co3O4-x nanorods to enhance the electrocatalytic hydrolysis performance. As a result, the overpotentials of HER and OER are only 281 and 418 mV at a high current density of 100 mA cm-2 in 1.0 M KOH, respectively. An overall water electrolytic cell using CoMoP@Co3O4-x nanorods as both electrodes can reach 10 mA cm-2 at 1.614 V with outstanding durability. The improvement is realized by the synergistic effect of oxygen vacancies, Mo/P doping, and core-shell heterostructures for modulating the electronic structure and producing more active sites, which suggests a promising method for developing cost-effective and stable electrocatalysts.

14.
Int J Med Sci ; 18(16): 3652-3664, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34790037

RESUMO

Aim: In the late stage of atherosclerosis, the endothelial barrier of plaque is destroyed. The rapid deposition of oxidized lipids in the circulation leads to migration of numerous smooth muscle cells and macrophages, as well as foaming necrosis. The plaque progresses rapidly, and vulnerable plaques can easily induce adverse cardiovascular events. Here, we take the principle of gene editing to transfer the liver to express the LOX-1 receptor which is more sensitive to Ox-LDL by using AAV8 containing a liver-specific promoter. In this way, we want to explore whether the progress of advanced atherosclerosis and the stability of advanced plaque can be improved when the liver continues to clear Ox-LDL from the circulation. Methods and Results: In order to explore the effect of the physiological and continuous elimination of Ox-LDL through the liver on advanced atherosclerosis, we chose ApoE-/- mice in high-fat diet for 20 weeks. After 16 weeks of high-fat diet, the baseline group was sacrificed and the specimens were collected. The virus group and the control group were injected with the same amount of virus dilution and normal saline through the tail vein, and continued to feed until 20 weeks of high-fat diet, and then sacrificed to collect specimens. The results showed that LOX-1 was ectopically and functionally expressed in the liver as an Ox-LDL receptor, reducing the content of it in circulation. Compared with the control group, the degree of plaque progression in the virus group was significantly reduced, similar to the baseline group, the plaque necrosis core decreased, and the collagen fiber content increased. In addition, there are more contractile smooth muscle cells in the plaques of the virus group instead of synthetic ones, and the content of macrophages was also reduced. These data suggested that the virus group mice have greatly increased advanced plaque stability compared with the control group mice. Conclusions: Due to the destruction of endothelial barrier in advanced plaques, rapid deposition of Ox-LDL can result in fast plaque progression, increased necrotic cores, and decreased stability. Our research shows that the use of AAV8 through gene editing allows the liver to express LOX-1 receptors that are more sensitive to Ox-LDL, so that it can continue to bind Ox-LDL in the circulation and exploit the liver's strong lipid metabolism ability to physiologically clear Ox-LDL, which can inhibit the rapid progress of advanced plaque and increase the stability of plaque.


Assuntos
Aterosclerose/metabolismo , Lipoproteínas LDL/metabolismo , Fígado/metabolismo , Placa Aterosclerótica/metabolismo , Animais , Apolipoproteínas E/genética , Aterosclerose/patologia , Progressão da Doença , Humanos , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Knockout , Placa Aterosclerótica/patologia , Placa Aterosclerótica/prevenção & controle , Receptores Depuradores Classe E/genética , Receptores Depuradores Classe E/metabolismo , Células THP-1
15.
ACS Appl Mater Interfaces ; 13(47): 56682-56691, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34791877

RESUMO

The Li metal anode is considered one of the most potential anodes due to its highest theoretical specific capacity and the lowest redox potential. However, the scalable preparation of safe Li anodes remains a challenge. In the present study, a LiF-rich protection layer has been developed using self-driven chemical reactions between the Li3xLa2/3-xTiO3/polyvinylidene fluoride/dimethylacetamide (LLTO/PVDF/DMAc) solution and the Li metal. After coating the LLTO/PVDF/DMAc solution to Li foil, PVDF reacted with Li spontaneously to form LiF, and the accompanying Ti4+ ions (in LLTO) were reduced to Ti3+ to form a mixed ionic and electronic conductor LixLLTO. The protective layer can redistribute the Li-ion transport, regulate the even Li deposition, and inhibit the Li dendrite growth. When paired with LiFePO4, NCM811, and S cathodes, the batteries have demonstrated excellent capacity retention and cycling stability. More importantly, a volumetric energy density of 478 Wh L-1 and 78% capacity retention after 310 cycles have been achieved by using a S/LixLLTO-Li pouch cell. This work provides a feasible avenue to provide large-scale preparation of safe Li anodes for the next-generation pouch-type Li-S batteries as ideal power sources for flexible electronic devices.

16.
Sci Adv ; 7(34)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34417183

RESUMO

High-entropy alloys (HEAs), as an emerging class of materials, have pointed a pathway in developing alloys with interesting property combinations. Although they are not exempted from the strength-ductility trade-off, they present a standing chance in overcoming this challenge. Here, we report results for a precipitation-strengthening strategy, by tuning composition to design a CoNiV-based face-centered cubic/B2 duplex HEA. This alloy sustains ultrahigh gigapascal-level tensile yield strengths and excellent ductility from cryogenic to elevated temperatures. The highest specific yield strength (~150.2 MPa·cm3/g) among reported ductile HEAs is obtained. The ability of the alloy presented here to sustain this excellent strength-ductility synergy over a wide temperature range is aided by multiple deformation mechanisms i.e., twins, stacking faults, dynamic strain aging, and dynamic recrystallization. Our results open the avenue for designing precipitation-strengthened lightweight HEAs with advanced strength-ductility combinations over a wide service temperature range.

17.
J Colloid Interface Sci ; 601: 346-354, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34087595

RESUMO

TiO2 nanostructures have been one of the most explored metal oxides photocatalysts to apply for environmental remediation. However, its wide band gap results in the underutilization of sunlight for degradation of pollutants. In order to overcome this handicap, the synthesis of TiO2-based composite has brought extraordinary materials. In this study, we design and prepare TiO2/Nb2O5 heterostructures with different molar ratios by using peroxotitanium and peroxoniobium complex as precursors in aqueous solution. The TiO2 exists in the form of anatase while Nb2O5 is amorphous in the composite, leading to a special crystalline TiO2/amorphous Nb2O5 heterostructures. In particular, Nb element is also doped and Ti3+ ions are formed in the TiO2 lattice, leading to a reduced band gap. The unique TiO2/0.25Nb2O5 (Ti:Nb = 2:1) heterostructures can effectively suppress the recombination of photogenerated electrons and holes, and facilitate the charge transfer, resulting in the optimum photocatalytic performance. The nitrogen oxide removal efficiency by TiO2/0.25Nb2O5 is 77.23% in visible light, which is 3.8-folds and 7.0-folds higher than pure TiO2 and Nb2O5. Photocatalytic degradation of acetaminophen by TiO2/0.25Nb2O5 is 90.6% in visible light, which is approximately 2.5-folds higher than pure TiO2 and Nb2O5.


Assuntos
Acetaminofen , Nióbio , Catálise , Óxidos de Nitrogênio , Titânio
18.
J Med Internet Res ; 23(2): e23786, 2021 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-33616534

RESUMO

BACKGROUND: Noncommunicable diseases (NCDs) are associated with the burden of premature deaths and huge medical costs globally. There is an increasing number of studies combining a multiple health behavior change (MHBC) intervention paradigm with eHealth approaches to jointly promote weight-related health behaviors among people with NCD; yet, a comprehensive summary of these studies is lacking. OBJECTIVE: This review aims to meta-analyze the effectiveness and systematically summarize the characteristics of the relevant intervention studies for improving the outcomes of physical activity, healthy diet, and weight among people with NCD. METHODS: Following PRISMA guidelines, 4 electronic databases (PsycINFO, PubMed, Scopus, SPORTDiscus) were systematically searched to identify eligible articles based on a series of inclusion and exclusion criteria. Article selection, quality assessment, and data extraction were independently performed by 2 authors. The standardized mean difference (SMD) was calculated to evaluate the effectiveness of interventions for 3 intervention outcomes (physical activity, healthy diet, and weight), and subsequent subgroup analyses were performed for gender, age, intervention duration, channel, and theory. Calculations were conducted, and figures were produced in SPSS 22 and Review Manager 5.3. RESULTS: Of the 664 original hits generated by the systematic searches, 15 eligible studies with moderate to high quality were included. No potential publication bias was detected using statistical analyses. Studies varied in intervention channel, intensity, and content. The meta-analysis revealed that the eHealth MHBC interventions significantly promoted physical activity (SMD 0.85, 95% CI 0.23 to 1.47, P=.008) and healthy diet (SMD 0.78, 95% CI 0.13 to 1.43, P=.02), but did not contribute to a healthy weight status (SMD -0.13, 95% CI= -0.47 to 0.20, P=.43) among people with NCDs, compared to the control conditions. Results from subgroup analysis indicated that theory-based interventions achieved greater effect than nontheory-based interventions in promoting physical activity, and interventions with traditional approaches (SMS, telephone) were more effective than those with modern internet-based approaches in promoting healthy diet. CONCLUSIONS: The results of this review indicates that eHealth MHBC interventions achieve preliminary success in promoting physical activity and healthy diet behaviors among people with NCD. Future studies could improve the intervention design to achieve better intervention effectiveness. TRIAL REGISTRATION: PROSPERO International Prospective Register of Systematic Reviews CRD42019118629; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=118629.


Assuntos
Dieta Saudável/métodos , Exercício Físico/fisiologia , Comportamentos Relacionados com a Saúde/fisiologia , Doenças não Transmissíveis/reabilitação , Telemedicina/métodos , Humanos
19.
J Colloid Interface Sci ; 589: 308-317, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33472150

RESUMO

Sn@Graphene composites as anode materials in Lithium-ion batteries have attracted intensive interest due to the inherent high capacity. On the other side, the high atomic ratio (Li4.4Sn) induces the pulverization of the electrode with cycling. Thus, suppressing pulverization by designing the structure of the materials is an essential key for improving cyclability. Applying the nanotechnologies such as electrospinning, soft/hard nano template strategy, surface modification, multi-step chemical vapor deposition (CVD), and so on has demonstrated the huge advantage on this aspect. These strategies are generally used for homogeneous dispersing Sn nanomaterials in graphene matrix or constructing the voids in the inner of the materials to obtain the mechanical buffer effect. Unfortunately, these processes induce huge energy consumption and complicated operation. To solve the issue, new nanotechnology for the composites by the bottom-up strategy (Organic Molecule Confinement Reaction (OMCR)) was shown in this report. A 3D organic nanoframes was synthesized as a graphene precursor by low energy nano emulsification and photopolymerization. SnO2 nanoparticles@3D organic nanoframes as the composites precursor were in-situ formed in the hydrothermal reaction. After the redox process by the calcination, the Sn nanoparticles with nanovoids (~100 nm, uniform size) were homogeneously dispersed in a Two-Dimensional Laminar Matrix of graphene nanosheets (2DLMG) by the in-situ patterning and confinement effect from the 3D organic nanoframes. The pulverization and crack of the composites were effectively suppressed, which was proved by the electrochemical testing. The Sn nanoparticles@2DLMG not delivered just the high cyclability during 200 cycles, but also firstly achieved a high specific capacity (539 mAh g-1) at the low loading Sn (19.58 wt%).

20.
ACS Nano ; 14(12): 17285-17294, 2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33211956

RESUMO

The introduction of a dual-functional interlayer into lithium-sulfur batteries (LSBs) provides many opportunities for restraining the "shuttle effect" and enhancing sluggish sulfur conversion kinetics. Tuning the band structure of the metal sulfide provides an opportunity to enhance its catalytic activity, which plays an important role in suppressing the "shuttle effect" of lithium polysulfides (LiPSs) in LSBs. Here were present a Co9S8@MoS2 core-shell heterostructure anchored to a carbon nanofiber (Co9S8@MoS2/CNF), developed as an interlayer for suppressing the shuttle effect of LiPSs. The fabricated composite heterostructure is determined to be an effective alternative material that combines the synergistic relationship between chemisorption and electrochemical catalysis. We find that the band structure of the MoS2 shell can be effectively tuned by the Co9S8 core and that the Co9S8@MoS2/CNF can capture the LiPSs, providing excellent catalytic ability to convert LiPSs into Li2S2, with subsequent transformation from Li2S2 to Li2S. Importantly, high capacities of 1002 and 986 mAh g-1 can be retained after 50 cycles with high-sulfur loadings of 6 and 10 mg cm-2. Our results highlight the design of an atomic-scale heterostructure as a multifunctional interlayer providing a synergistic relationship between adsorption and catalysis. The net result is an effective retardation of the shuttling of LiPSs and an enhancement of the electrochemical redox reactions of LiPSs. This work shows great promise toward the development of practical applications of LSBs.

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