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1.
Angew Chem Int Ed Engl ; : e202408989, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38837505

RESUMEN

The extensive industrial applications of fuel oil, a critical strategic resource, are accompanied by significant environmental and health concerns due to the presence of sulfur-containing compounds in its composition, which result in hazardous combustion waste. Extensive research has been conducted to develop technologies for low-vulcanization fuel production to address this issue. Consequently, the investigation of catalysts for environmentally friendly and safe photocatalytic desulfurization becomes imperative. To that end, we have designed efficient MIL-101(Fe)/CQDs@g-C3N4 (MIL101/CDs-C3N4) Z-scheme heterojunction photocatalysts with high carrier separation and mobility through a thermal polymerization-hydrothermal strategy. The high concentration of photogenerated carriers facilitates the activation of oxygen and H2O2, leading to increased production of ROS (⋅O2 -, ⋅OH, h+), thereby enhancing the photocatalytic desulfurization (PODS). Additionally, DFT (Density functional theory) calculations were utilized to determine the electron migration pathways of the catalysts and adsorption energies of DBT (dibenzothiophene). Moreover, Gibbs free energy calculations indicated that MIL101/CDs-C3N4 exhibited the lowest activation energy for oxygen and H2O2. The mechanism of photocatalytic desulfurization was proposed through a combination of theoretical calculations and experimental studies. This study provides guidance for the development of MOF-based Z-scheme systems and their practical application in desulfurization processes.

2.
Adv Mater ; 36(19): e2400237, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38321816

RESUMEN

The sluggish ions-transfer and inhomogeneous ions-nucleation induce the formation of randomly oriented dendrites on Zn anode, while the chemical instability at anode-electrolyte interface triggers detrimental side reactions. Herein, this report in situ designs a multifunctional hybrid interphase of Bi/Bi2O3, for the first time resulting in a novel synergistic regulation mechanism involving: (i) chemically inert interface protection mechanism suppresses side reactions; and more fantastically, (ii) innovative thermodynamically favorable Zn atomic clusters dissociation mechanism impedes dendrites formation. Assisted by collaborative modulation behavior, the Zn@Bi/Bi2O3 symmetry cell delivers an ultrahigh cumulative plating capacity of 1.88 Ah cm-2 at 5 mA cm-2 and ultralong lifetimes of 300 h even at high current density and depth of discharge (10 mA cm-2, DODZn: 60%). Furthermore, under a low electrolyte-to-capacity ratio (E/C: 45 µL mAh-1) and negative-to-positive capacity ratio (N/P: 6.3), Zn@Bi/Bi2O3||MnO2 full-cell exhibits a superior capacity retention of 86.7% after 500 cycles at 1 A g-1, which outperforms most existing interphases. The scaled-up Zn@Bi/Bi2O3||MnO2 battery module (6 V, 1 Ah), combined with the photovoltaic panel, presents excellent renewable-energy storage ability and long output lifetime (12 h). This work provides a fantastic synergistic mechanism to achieve the ultrastable Zn anode and can be greatly promised to apply it into other metal-based batteries.

3.
Small ; : e2304530, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38415903

RESUMEN

Elevating the working temperature delivers a simple and universal approach to enhance the energy storage performances of supercapacitors owing to the fundamental improvements in ion transportation kinetics. Among all heating methods, introducing green and sustainable photothermal heating on supercapacitors (SCs) is highly desired yet remains an open challenge, especially for developing an efficient and universal photothermal heating strategy that can be generally applied to arbitrary SC devices. Flash-enabled graphene (FG) absorbers are produced through a simple and facile flash reduction process, which can be coated on the surface of any SC devices to lift their working temperature via a photothermal effect, thus, improving their overall performance, including both power and energy densities. With the systematic temperature-dependent investigation and the in-depth numerical simulation of SC performances, an evident enhancement in capacitance up to 65% can be achieved in photothermally enhanced SC coin cell devices with FG photo-absorbers. This simple, practical, and universal enhancement strategy provides a novel insight into boosting SC performances without bringing complexity in electrode fabrication/optimization. Also, it sheds light on the highly efficient utilization of green and renewable photothermal energies for broad application scenarios, especially for energy storage devices.

4.
Nanomicro Lett ; 16(1): 70, 2024 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-38175329

RESUMEN

Over the past decade, graphitic carbon nitride (g-C3N4) has emerged as a universal photocatalyst toward various sustainable carbo-neutral technologies. Despite solar applications discrepancy, g-C3N4 is still confronted with a general fatal issue of insufficient supply of thermodynamically active photocarriers due to its inferior solar harvesting ability and sluggish charge transfer dynamics. Fortunately, this could be significantly alleviated by the "all-in-one" defect engineering strategy, which enables a simultaneous amelioration of both textural uniqueness and intrinsic electronic band structures. To this end, we have summarized an unprecedently comprehensive discussion on defect controls including the vacancy/non-metallic dopant creation with optimized electronic band structure and electronic density, metallic doping with ultra-active coordinated environment (M-Nx, M-C2N2, M-O bonding), functional group grafting with optimized band structure, and promoted crystallinity with extended conjugation π system with weakened interlayered van der Waals interaction. Among them, the defect states induced by various defect types such as N vacancy, P/S/halogen dopants, and cyano group in boosting solar harvesting and accelerating photocarrier transfer have also been emphasized. More importantly, the shallow defect traps identified by femtosecond transient absorption spectra (fs-TAS) have also been highlighted. It is believed that this review would pave the way for future readers with a unique insight into a more precise defective g-C3N4 "customization", motivating more profound thinking and flourishing research outputs on g-C3N4-based photocatalysis.

5.
J Colloid Interface Sci ; 658: 627-638, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38134671

RESUMEN

2D/2D Ni-MOF/g-C3N4 nanocomposite was utilized for desulfurization. The multilayer pore structure and high specific surface area of Ni-MOF/g-C3N4 promote the adsorption and conversion of thiophene. In addition, the two-dimensional structure exposes more active centers and shortens photogenerated carrier migration to the material surface distance, it enhances photogenerated charge transfer. The Ni-MOF and g-C3N4 construct a Z-scheme heterojunction structure with tight contact, it effectively enhances the material's photocatalytic redox ability. In the light, the material generates more photocarriers for the production of free radicals including hydroxyl radicals, holes, and superoxide radicals. The higher carrier concentration of Ni-MOF/g-C3N4 promotes the activation and oxidation of thiophene, consequently enhancing the photocatalytic desulfurization capability. The results showed that the conversion of thiophene was 98.82 % in 3 h under visible light irradiation. Radical capture experiments and analysis using electron paramagnetic resonance spectroscopy demonstrated that superoxide radicals, holes, and hydroxyl radicals played crucial roles in PODS (photocatalytic oxidative desulfurization). In addition, DFT (density functional theory) calculations were conducted to determine the paths of electron migration and TH (thiophene) adsorption energy. Finally, a mechanism for photocatalytic desulfurization was proposed based on the comprehensive analysis of theoretical calculations and experimental studies.

6.
J Colloid Interface Sci ; 652(Pt B): 1184-1196, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37657218

RESUMEN

Ni-rich layered structure ternary oxides, such as LiNi0.8Co0.1Mn0.1O2 (NCM811), are promising cathode materials for high-energy lithium-ion batteries (LIBs). However, a trade-off between high capacity and long cycle life still obstructs the commercialization of Ni-rich cathodes in modern LIBs. Herein, a facile dual modification approach for improving the electrochemical performance of NCM811 was enabled by a typical perovskite oxide: strontium titanate (SrTiO3). With a suitable thermal treatment, the modified cathode exhibited an outstanding electrochemical performance that could deliver a high discharge capacity of 188.5 mAh/g after 200 cycles under 1C with a capacity retention of 90%. The SrTiO3 (STO) protective layer can effectively suppress the side reaction between the NCM811 and the electrolyte. In the meantime, the pillar effect provided by interfacial Ti doping could effectively reduce the Li+/Ni2+ mixing ratio on the NCM811 surface and offer more efficient Li+ migration between the cathode and the coating layer after post-thermal treatment (≥600 °C). This dual modification strategy not only significantly improves the structural stability of Ni-rich layered structure but also enhances the electrochemical kinetics via increasing diffusion rate of Li+. The electrochemical measurement results further disclosed that the 3 wt% STO coated NCM811 with 600 °C annealing exhibits the best performance compared with other control samples, suggesting an appropriate temperature range for STO coated NCM811 cathode is critical for maintaining a stable structure for the whole system. This work may offer an effective option to enhance the electrochemical performance of Ni-rich cathodes for high-performance LIBs.

7.
Small ; 19(45): e2304913, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37434105

RESUMEN

Zn dendrite formation is the main obstacle to commercializing aqueous zinc-ion batteries (ZIBs). α-cyclodextrin (α-CD) is proposed as an environmentally friendly macromolecule additive in the ZnSO4 -based electrolyte to obtain stable and reversible Zn anodes. The results show that α-CD molecules' unique 3D structure can effectively regulate the mass transfer of the electrolyte components and isolate the Zn anode from H2 O molecules. The α-CD provides abundant electrons to the Zn (002) crystallographic plane, which induces charge density redistribution. Such an effect relieves the reduction and aggregation of Zn2+ cations while protecting the Zn metal anode from water molecules. Finally, a small amount of α-CD additive (0.01 M) can enhance the performance of Zn significantly in Zn||Cu cells (1980 cycles with 99.45% average CE) and Zn||Zn cells (8000 h ultra-long cycle life). The excellent practical applicability was further verified in Zn||MnO2 cells.

8.
ACS Appl Mater Interfaces ; 15(24): 29308-29320, 2023 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-37279402

RESUMEN

Ni-rich layered ternary cathodes (i.e., LiNixCoyMzO2, M = Mn or Al, x + y + z = 1 and x ≥ 0.8) are promising candidates for the power supply of portable electronic devices and electric vehicles. However, the relatively high content of Ni4+ in the charged state shortens their lifespan due to inevitable capacity and voltage deteriorations during cycling. Therefore, the dilemma between high output energy and long cycle life needs to be addressed to facilitate more widespread commercialization of Ni-rich cathodes in modern lithium-ion batteries (LIBs). This work presents a facile surface modification approach with defect-rich strontium titanate (SrTiO3-x) coating on a typical Ni-rich cathode: LiNi0.8Co0.15Al0.05O2 (NCA). The defect-rich SrTiO3-x-modified NCA exhibits enhanced electrochemical performance compared to its pristine counterpart. In particular, the optimized sample delivers a high discharge capacity of ∼170 mA h/g after 200 cycles under 1C with capacity retention over 81.1%. The postmortem analysis provides new insight into the improved electrochemical properties which are ascribed to the SrTiO3-x coating layer. This layer appears to not only alleviate the internal resistance growth, from uncontrollable cathode-electrolyte interface evolution, but also acts as a lithium diffusion channel during prolonged cycling. Therefore, this work offers a feasible strategy to improve the electrochemical performance of layered cathodes with high nickel content for next-generation LIBs.

9.
Small ; : e2302500, 2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-37259673

RESUMEN

Defect engineering has been regarded as an "all-in-one strategy" to alleviate the insufficient solar utilization in g-C3 N4 . However, without appropriate modification, the defect benefits will be partly offset due to the formation of deep localized defect states and deteriorated surface states, lowering the photocarrier separation efficiency. To this end, the defective g-C3 N4 is designed with both S dopants and N vacancies via a dual-solvent-assisted synthetic approach. The precise defect control is realized by the addition of ethylene glycol (EG) into precursor formation and molten sulfur into the pyrolysis process, which simultaneously induced g-C3N4. with shallow defect states. These shallow defect energy levels can act as a temporary electron reservoir, which are critical to evoke the migrated electrons from CB with a moderate trapping ability, thus suppressing the bulky photocarrier recombination. Additionally, the optimized surface states of DCN-ES are also demonstrated by the highest electron-trapping resistance (Rtrapping ) of 9.56 × 103 Ω cm2 and the slowest decay kinetics of surface carriers (0.057 s-1 ), which guaranteed the smooth surface charge transfer rather than being the recombination sites. As a result, DCN-ES exhibited a superior H2 evolution rate of 4219.9 µmol g-1 h-1 , which is 29.1-fold higher than unmodified g-C3 N4 .

10.
Nanomicro Lett ; 15(1): 132, 2023 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-37211571

RESUMEN

Covalent organic frameworks (COFs) have emerged as a kind of rising star materials in photocatalysis. However, their photocatalytic activities are restricted by the high photogenerated electron-hole pairs recombination rate. Herein, a novel metal-free 2D/2D van der Waals heterojunction, composed of a two-dimensional (2D) COF with ketoenamine linkage (TpPa-1-COF) and 2D defective hexagonal boron nitride (h-BN), is successfully constructed through in situ solvothermal method. Benefitting from the presence of VDW heterojunction, larger contact area and intimate electronic coupling can be formed between the interface of TpPa-1-COF and defective h-BN, which make contributions to promoting charge carriers separation. The introduced defects can also endow the h-BN with porous structure, thus providing more reactive sites. Moreover, the TpPa-1-COF will undergo a structural transformation after being integrated with defective h-BN, which can enlarge the gap between the conduction band position of the h-BN and TpPa-1-COF, and suppress electron backflow, corroborated by experimental and density functional theory calculations results. Accordingly, the resulting porous h-BN/TpPa-1-COF metal-free VDW heterojunction displays outstanding solar energy catalytic activity for water splitting without co-catalysts, and the H2 evolution rate can reach up to 3.15 mmol g-1 h-1, which is about 67 times greater than that of pristine TpPa-1-COF, also surpassing that of state-of-the-art metal-free-based photocatalysts reported to date. In particular, it is the first work for constructing COFs-based heterojunctions with the help of h-BN, which may provide new avenue for designing highly efficient metal-free-based photocatalysts for H2 evolution.

11.
Chem Asian J ; 17(11): e202200095, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35355439

RESUMEN

Infectious diseases caused by bacteria intimidate the health of human beings all over the world. Although many avenues have been tried, various operating conditions limit their actual applications. Photocatalytic nanomaterials are becoming candidates to be competent for water purification. Here, a novel and more efficient S-scheme has been engineered between two dimensional (2D) layered phosphorus-doped graphitic carbon nitride (P-g-C3 N4 ) and BiOBr via hydrothermal polymerization to inhibit the recombination of charge and broaden light absorption. The as-prepared P-g-C3 N4 /BiOBr hybrids exhibits significantly improved photocatalytic disinfection contrast to g-C3 N4 /BiOBr in visible wavelengths, suggesting phosphorus doping which adjusts the band structure plays a significant role in the S-scheme system. And the sterilization rate of multidrug-resistant Acinetobacter baumannii 28 (AB 28) was 99.9999% within 80 min and Staphylococcus aureus (S. aureus) was 99.9%.


Asunto(s)
Desinfección , Staphylococcus aureus , Bismuto , Catálisis , Grafito , Humanos , Luz , Compuestos de Nitrógeno , Fósforo
12.
J Inorg Biochem ; 230: 111720, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35221123

RESUMEN

In vivo toxicity of aromatic ring (BODIPY, 1,3,5,7,8-pentamethyl dipyrrin borondifluoride) attached monofunctional Pt(II) complexes mCBP {[cis-Pt(NH3)2Cl] 8-(para-pyridine-methylene),1,3,5,7-tetramethyl dipyrrin borondifluoride}+ Nitrate- and dCBP {[cis-Pt(NH3)2Cl]28-(1,3-pyrimidine-5-methylene),1,3,5,7-tetramethyl dipyrrin borondifluoride}2+ diNitrate2- were tested in Caenorhabditis elegans (C. elegans). dCBP showed promising reactive oxygen ROS (reactive oxygen species) generating capability. This complex resulted reduction of lifespan, body length and egg laying rate under dark and light irradiation in both N2 (wild-type, cisplatin resistant) and ok938 (asna-1, cisplatin sensitive) C. elegans. Expressional change of several key cancer related pathway (JNK (c-Jun N-terminal kinase) and Wnt/ß-catenin (Wingless/Integrated/ß-catenin)) related genes (for instance, jnk-1, wrm-1 and gst-4) were confirmed by RNA sequencing experiments. These transcriptional alternations could explain physiological parameters change in nematode and partially revealed how both Pt(II) based complexes influence cancer related pathways. Furthermore, these associated genes exhibited the function of apoptosis, reduced chemoresistance of cancer cells and most of those expressional changes were linked to extended survival of cancer patients.


Asunto(s)
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Platino (Metal)/farmacología , Animales , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Cisplatino/farmacología , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/metabolismo , Proteínas del Citoesqueleto/farmacología , Humanos , Especies Reactivas de Oxígeno/metabolismo , beta Catenina/metabolismo , beta Catenina/farmacología
13.
Chem Asian J ; 16(22): 3774-3780, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34605208

RESUMEN

Sodium-ion batteries are promising energy-storage systems, but they are facing huge challenges for developing fast-charging anode materials. Bismuth (Bi)-based anode materials are considered as candidates for fast-charging anodes of sodium-ion batteries due to their excellent rate performance. Herein, we designed a two-dimensional Bi/MXene anode material based on a hydrogen thermal reduction strategy. Benefitting from microstructure advantages, Bi/MXene anodes exhibited an excellent rate capability and superior cycle performance in Na//Bi/MXene half-batteries and Na3 V2 (PO4 )3 /C//Bi/MXene full-batteries. Moreover, full-batteries can complete a charge/discharge cycle in 7 min and maintain an excellent cycle life (over 7000 cycles). The electrochemical test results showed that Bi/MXene is a promising anode material with fast charge/discharge capability for sodium-ion batteries.

14.
Adv Mater ; 33(29): e2003666, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34096100

RESUMEN

Lithium-ion batteries, which have revolutionized portable electronics over the past three decades, were eventually recognized with the 2019 Nobel Prize in chemistry. As the energy density of current lithium-ion batteries is approaching its limit, developing new battery technologies beyond lithium-ion chemistry is significant for next-generation high energy storage. Lithium-sulfur (Li-S) batteries, which rely on the reversible redox reactions between lithium and sulfur, appears to be a promising energy storage system to take over from the conventional lithium-ion batteries for next-generation energy storage owing to their overwhelming energy density compared to the existing lithium-ion batteries today. Over the past 60 years, especially the past decade, significant academic and commercial progress has been made on Li-S batteries. From the concept of the sulfur cathode first proposed in the 1960s to the current commercial Li-S batteries used in unmanned aircraft, the story of Li-S batteries is full of breakthroughs and back tracing steps. Herein, the development and advancement of Li-S batteries in terms of sulfur-based composite cathode design, separator modification, binder improvement, electrolyte optimization, and lithium metal protection is summarized. An outlook on the future directions and prospects for Li-S batteries is also offered.

15.
Chem Asian J ; 16(16): 2314-2320, 2021 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-34159728

RESUMEN

As two-dimensional (2D) materials, bismuth (Bi) has large interlayer spacing along c-axis (0.395 nm) which provides rich active sites for sodium ions, thus guaranteeing high sodium ion storage activity. However, its poor electrical conductivity, combined with its degraded cycling performance, restricts its practical application. Herein, Bi microsphere coated with nitrogen-doped carbon (Bi@NC) was synthesized. Owing to the unique Bi crystals and nitrogen-doped carbon layer, the obtained Bi@NC anode exhibited satisfactory cycling stability and superior rate capability. Moreover, after assembling Bi@NC anode with Na3 V2 (PO4 )3 @C cathode to full battery, excellent sodium storage performance was obtained (57 mA h g-1 after 2000 cycles at 1.0 A g-1 ).

16.
Chem Asian J ; 16(14): 1949-1955, 2021 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-34041869

RESUMEN

We discovered that the 2D Ti3 C2 Tx MXene sheet displays an ultra-high removal capability for bilirubin (BR). In particular, MXene shows 47.6 times higher removal efficiency over traditional activated carbon absorbents. The effect of MXene on the removal rate of BR in BR solution containing different concentrations of bovine serum albumin (BSA) was studied. The adsorption capacity of BSA for BR at high concentration of 5 g L-1 was about 85% of the best adsorption capacity. The MXene before and after adsorption was characterized by SEM, FT-IR and XPS. Furthermore, MXene beads were prepared, and the hemoperfusion simulation experiment was carried out. The results show that the adsorption capacity of MXene for bilirubin can reach 1192.9 mg g-1 . This study suggests that MXene may be promising in the treatment of hyperbilirubinemia.


Asunto(s)
Bilirrubina/química , Cerámica/química , Adsorción , Animales , Carbono/química , Bovinos , Albúmina Sérica Bovina/química , Titanio/química
17.
Adv Mater ; 32(32): e2000960, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32578274

RESUMEN

Solid-electrolyte-based molten-metal batteries have attracted considerable attention for grid-scale energy storage. Although ZEBRA batteries are considered one of the promising candidates, they still have the potential concern of metal particle growth and ion exchange with the ß"-Al2 O3 electrolyte. Herein, a Li6.4 La3 Zr1.4 Ta0.6 O12 solid-electrolyte-based molten lithium-molybdenum-iron(II) chloride battery (denoted as Li-Mo-FeCl2 ) operated at temperature of 250 °C, comprising a mixture of Fe and LiCl cathode materials, a Li anode, a garnet-type Li-ion ceramic electrolyte, and Mo additive, is designed to overcome these obstacles. Different from conventional battery reaction mechanisms, this battery revolutionarily synchronizes the reversible Fe-Mo alloying-dealloying reactions with the delithiation-lithiation processes, meaning that the porous Mo framework derived from Fe-Mo alloy simultaneously suppresses the growth of pure Fe particles. By adopting a Li anode and a Li-ion ceramic electrolyte, the corrosion problem between the cathode and the solid electrolyte is overcome. With similar battery cost ($12 kWh-1 ), the theoretical energy density of Li-Mo-FeCl2 battery surpasses that of a Na-FeCl2 ZEBRA battery over 25%, to 576 Wh kg-1 and 2216 Wh L-1 , respectively. Experimental results further prove this cell has excellent cycling performance (472 mAh gLiCl -1 after 300 cycles, 50 mg active material) and strong tolerance against the overcharge-overdischarge (3-1.6 V) and freezing-thawing (25-250 °C) incidents.

18.
Mikrochim Acta ; 186(7): 481, 2019 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-31250184

RESUMEN

A photoelectrochemical (PEC) sensor was constructed for the detection of non-electroactive malathion. It is based on the use of a hierarchical CuO material derived from a Cu-BTC metal-organic framework (where BTC stands for benzene-1,3,5-tricarboxylic acid). The modified CuO was obtained by calcination of Cu-BTC at a high temperature (300 °C) and possesses a high photocurrent conversion efficiency. Under irradiation with visible light and in the presence of malathion, the formation of the CuO-malathion complex on the CuO gave rise to an increase in steric hindrance. This results in a decrease in photocurrent. This novel PEC detection method has a lower detection limit of 8.6 × 10-11 mol L-1 and a wide linear range (1.0 × 10-10 ~ 1.0 × 10-5 mol L-1). Graphical abstract Schematic presentation of the Cu-BTC MOF derived photoelectrochemical sensor for non-electroactive malathion detection.

19.
ACS Nano ; 13(4): 4731-4741, 2019 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-30924635

RESUMEN

Lithium-sulfur (Li-S) batteries have been regarded as one of the most promising candidates for next-generation energy storage owing to their high energy density and low cost. However, the practical deployment of Li-S batteries has been largely impeded by the low conductivity of sulfur, the shuttle effect of polysulfides, and the low areal sulfur loading. Herein, we report the synthesis of uniform Co-Fe mixed metal phosphide (Co-Fe-P) nanocubes with highly interconnected-pore architecture to overcome the main bottlenecks of Li-S batteries. With the highly interconnected-pore architecture, inherently metallic conductivity, and polar characteristic, the Co-Fe-P nanocubes not only offer sufficient electrical contact to the insulating sulfur for high sulfur utilization and fast redox reaction kinetics but also provide abundant adsorption sites for trapping and catalyzing the conversion of lithium polysulfides to suppress the shuttle effect, which is verified by both the comprehensive experiments and density functional theory calculations. As a result, the sulfur-loaded Co-Fe-P (S@Co-Fe-P) nanocubes delivered a high discharge capacity of 1243 mAh g-1 at 0.1 C and excellent cycling stability for 500 cycles with an average capacity decay rate of only 0.043% per cycle at 1 C. Furthermore, the S@Co-Fe-P electrode showed a high areal capacity of 4.6 mAh cm-2 with superior stability when the sulfur loading was increased to 5.5 mg cm-2. More impressively, the prototype soft-package Li-S batteries based on S@Co-Fe-P cathodes also exhibited superior cycling stability with great flexibility, demonstrating their great potential for practical applications.

20.
RSC Adv ; 9(35): 20424-20431, 2019 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-35514708

RESUMEN

A comparatively facile and ecofriendly process has been developed to synthesize porous carbon materials from Camellia oleifera shells. Potassium carbonate solution (K2CO3) impregnation is introduced to modify the functional groups on the surface of Camellia oleifera shells, which may play a role in promoting the development of pore structure during carbonization treatment. Moreover, a small amount of naturally embedded nitrogen and sulfur in the Camellia oleifera shells can also bring about the formation of pores. The Camellia oleifera shell-derived carbon has a large specific surface area of 1479 m2 g-1 with a total pore volume of 0.832 cm3 g-1 after being carbonized at 900 °C for 1 h. Furthermore, when used as an anode for lithium-ion batteries, the sample shows superior electrochemical performance with a specific capacity of 483 mA h g-1 after 100 cycles measured at 200 mA g-1 current density. Surprisingly, the specific capacity is even gradually increased with cycling. In addition, this sample exhibits almost 100% retention capacity after 250 cycles at a current density of 200 mA g-1.

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