Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Más filtros













Base de datos
Intervalo de año de publicación
1.
Nat Nanotechnol ; 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38684805

RESUMEN

Realizing the full potential of stretchable bioelectronics in wearables, biomedical implants and soft robotics necessitates conductive elastic composites that are intrinsically soft, highly conductive and strain resilient. However, existing composites usually compromise electrical durability and performance due to disrupted conductive paths under strain and rely heavily on a high content of conductive filler. Here we present an in situ phase-separation method that facilitates microscale silver nanowire assembly and creates self-organized percolation networks on pore surfaces. The resultant nanocomposites are highly conductive, strain insensitive and fatigue tolerant, while minimizing filler usage. Their resilience is rooted in multiscale porous polymer matrices that dissipate stress and rigid conductive fillers adapting to strain-induced geometry changes. Notably, the presence of porous microstructures reduces the percolation threshold (Vc = 0.00062) by 48-fold and suppresses electrical degradation even under strains exceeding 600%. Theoretical calculations yield results that are quantitatively consistent with experimental findings. By pairing these nanocomposites with near-field communication technologies, we have demonstrated stretchable wireless power and data transmission solutions that are ideal for both skin-interfaced and implanted bioelectronics. The systems enable battery-free wireless powering and sensing of a range of sweat biomarkers-with less than 10% performance variation even at 50% strain. Ultimately, our strategy offers expansive material options for diverse applications.

2.
Small ; 19(43): e2300242, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37381614

RESUMEN

Graphene with a 3D porous structure is directly laser-induced on lignocellulosic biopaper under ambient conditions and is further explored for multifunctional biomass-based flexible electronics. The mechanically strong, flexible, and waterproof biopaper is fabricated by surface-functionalizing cellulose with lignin-based epoxy acrylate (LBEA). This composite biopaper shows as high as a threefold increase in tensile strength and excellent waterproofing compared with pure cellulose one. Direct laser writing (DLW) rapidly induces porous graphene from the biopaper in a single step. The porous graphene shows an interconnected carbon network, well-defined graphene domains, and high electrical conductivity (e.g., ≈3 Ω per square), which can be tuned by lignin precursors and loadings as well as lasing conditions. The biopaper in situ embedded with porous graphene is facilely fabricated into flexible electronics for on-chip and paper-based applications. The biopaper-based electronic devices, including the all-solid-state planer supercapacitor, electrochemical and strain biosensors, and Joule heater, show great performances. This study demonstrates the facile, versatile, and low-cost fabrication of multifunctional graphene-based electronics from lignocellulose-based biopaper.

3.
Asian J Androl ; 2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36930541

RESUMEN

This study aimed to determine whether the abnormal deep layer of dartos fascia plays an important role in buried penis. Forty-nine patients with buried penis were treated with anatomical resection of the deep layer of dartos fascia under a microscope. Penile length was measured before and after completely resecting the deep layer to investigate the role of this layer in penile retraction. The superficial and deep layers of dartos fascia were collected from 49 patients with buried penis, the normal superficial layers were collected from 25 children/adults who underwent circumcision for nonmedical reasons, and the normal deep layers were collected from 20 adult cadavers. The penile fascia samples were stained with hematoxylin-eosin, Masson's trichrome, Sirius red, and Verhoeff's Van Gieson, and subjected to immunohistochemical examination and scanning electron microscopy. The penile shaft (mean ± standard deviation) was found to be significantly elongated after resecting the deep layer compared with that before resection (6.8 ± 1.9 cm vs 6.0 ± 1.6 cm, P < 0.001). An abnormal deep layer of dartos fascia characterized by disordered and fragmented elastic fibers was observed in 87.8% (43/49) of buried penis samples, whereas no abnormal deep layer was observed in normal penises from cadavers (0/20, P < 0.001). Thus, the abnormal deep layer of dartos fascia plays an important role in the buried penis. Its resection is helpful for avoiding recurrence.

4.
Sci Adv ; 9(1): eadf0575, 2023 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-36608138

RESUMEN

Liquid metal-elastomer composite is a promising soft conductor for skin-interfaced bioelectronics, soft robots, and others due to its large stretchability, ultrasoftness, high electrical conductivity, and mechanical-electrical decoupling. However, it often suffers from deformation-induced leakage, which can smear skin, deteriorate device performance, and cause circuit shorting. Besides, antimicrobial property is desirable in soft conductors to minimize microbial infections. Here, we report phase separation-based synthesis of porous liquid metal-elastomer composites with high leakage resistance and antimicrobial property, together with large stretchability, tissue-like compliance, high and stable electrical conductivity over deformation, high breathability, and magnetic resonance imaging compatibility. The porous structures can minimize leakage through damping effects and lower percolation thresholds to reduce liquid metal usage. In addition, epsilon polylysine is loaded into elastic matrices during phase separation to provide antimicrobial property. The enabled skin-interfaced bioelectronics can monitor cardiac electrical and mechanical activities and offer electrical stimulations in a mechanically imperceptible and electrically stable manner even during motions.

5.
Nano Lett ; 23(2): 597-605, 2023 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-36622320

RESUMEN

The development of high-performance miniaturized and flexible airflow sensors is essential to meet the need of emerging applications. Graphene-based airflow sensors are hampered by the sluggish response and recovery speed and low sensitivity. Here we employ laser-induced graphene (LIG) with poststructural biomimicry for fabricating high-performance, flexible airflow sensors, including cotton-like porous LIG, caterpillar fluff-like vertical LIG fiber, and Lepidoptera scale-like suspended LIG fiber (SLIGF) structures. The structural engineering changes the deformation behavior of LIGs under stress, among which the synchronous propagation of the scale-like structure of SLIGF is the most conducive to airflow sensing. The SLIGF achieves the shortest average response time of 0.5 s, the highest sensitivity of 0.11 s/m, and a record-low detection threshold of 0.0023 m/s, benchmarked against the state-of-the-art airflow sensors. Furthermore, we showcase the SLIGF airflow sensors in weather forecasting, health, and communications applications. Our study will help develop next-generation waterflow, sound, and motion sensors.

6.
Sci Adv ; 8(25): eabp9734, 2022 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-35731865

RESUMEN

Laser-assisted fabrication of conductive materials on flexible substrates has attracted intense interests because of its simplicity, easy customization, and broad applications. However, it remains challenging to achieve laser scribing of conductive materials on tissue-like soft elastomers, which can serve as the basis to construct bioelectronics and soft actuators. Here, we report laser scribing of metallic conductive, photoactive transition metal oxide (molybdenum dioxide) on soft elastomers, coated with molybdenum chloride precursors, under ambient conditions. Laser-scribed molybdenum dioxide (LSM) exhibits high electrical conductivity, biocompatibility, chemical stability, and compatibility with magnetic resonance imaging. In addition, LSM can be made on various substrates (polyimide, glass, and hair), showing high generality. Furthermore, LSM-based Janus on-skin electronics are developed to record information from human skin, human breath, and environments. Taking advantage of its outstanding photothermal effect, LSM-based soft actuators are developed to build light-driven reconfigurable three-dimensional architectures, reshapable airflow sensors, and smart robotic worms with bioelectronic sensors.

7.
Nat Commun ; 13(1): 524, 2022 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-35082331

RESUMEN

Concepts that draw inspiration from soft biological tissues have enabled significant advances in creating artificial materials for a range of applications, such as dry adhesives, tissue engineering, biointegrated electronics, artificial muscles, and soft robots. Many biological tissues, represented by muscles, exhibit directionally dependent mechanical and electrical properties. However, equipping synthetic materials with tissue-like mechanical and electrical anisotropies remains challenging. Here, we present the bioinspired concepts, design principles, numerical modeling, and experimental demonstrations of soft elastomer composites with programmed mechanical and electrical anisotropies, as well as their integrations with active functionalities. Mechanically assembled, 3D structures of polyimide serve as skeletons to offer anisotropic, nonlinear mechanical properties, and crumpled conductive surfaces provide anisotropic electrical properties, which can be used to construct bioelectronic devices. Finite element analyses quantitatively capture the key aspects that govern mechanical anisotropies of elastomer composites, providing a powerful design tool. Incorporation of 3D skeletons of thermally responsive polycaprolactone into elastomer composites allows development of an active artificial material that can mimic adaptive mechanical behaviors of skeleton muscles at relaxation and contraction states. Furthermore, the fabrication process of anisotropic elastomer composites is compatible with dielectric elastomer actuators, indicating potential applications in humanoid artificial muscles and soft robots.


Asunto(s)
Anisotropía , Materiales Biomiméticos/química , Elastómeros/química , Electricidad , Conductividad Eléctrica , Análisis de Elementos Finitos , Músculo Esquelético , Robótica/instrumentación
8.
iScience ; 24(7): 102736, 2021 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-34278252

RESUMEN

Skin-interfaced wearable electronics can find a broad spectrum of applications in healthcare, human-machine interface, robotics, and others. The state-of-the-art wearable electronics usually suffer from costly and complex fabrication procedures and nonbiodegradable polymer substrates. Paper, comprising entangled micro- or nano-scale cellulose fibers, is compatible with scalable fabrication techniques and emerges as a sustainable, inexpensive, disposable, and biocompatible substrate for wearable electronics. Given various attractive properties (e.g., breathability, flexibility, biocompatibility, and biodegradability) and rich tunability of surface chemistry and porous structures, paper offers many exciting opportunities for wearable electronics. In this review, we first introduce the intriguing properties of paper-based wearable electronics and strategies for cellulose modifications to satisfy specific demands. We then overview the applications of paper-based devices in biosensing, energy storage and generation, optoelectronics, soft actuators, and several others. Finally, we discuss some challenges that need to be addressed before practical uses and wide implementation of paper-based wearable electronics.

9.
Eur J Med Chem ; 224: 113690, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34256124

RESUMEN

Liver cancer most commonly develops in patients with chronic liver disease, the etiology of which includes viral hepatitis (B and C), alcohol, obesity, dietary carcinogens, and so forth. The current treatment modalities, including surgical resection and liver transplantation, have been found far from effective. Hence, there is an obvious critical need to develop alternative strategies for the treatment of it. In this review, we discuss the formation process and therapeutic targets of liver cancer. Currently, targeted therapy is limited to sorafenib, lenvatinib, regorafenib, ramucirumab and cabozantinib which leads to a survival benefit in patients, but on the other hand is hampered by the occurrence of drug resistance. Pleasingly and importantly, there are multiple natural products undergoing clinical evaluation in liver cancer, such as polyphenols like icaritin, resveratrol, and silybin, saponins including ginsenoside Rg3 and glycyrrhizinate, alkaloid containing irinotecan and berberine and inorganic compound arsenic trioxide at present. Preclinical and clinical studies have shown that these compounds inhibit liver cancer formation owing to the influence on the anti-viral, anti-inflammation, anti-oxidant, anti-angiogenesis and anti-metastasis activity. Furthermore, a series of small molecule derivatives inspired by the aforementioned compounds are designed and synthesized according to structure-activity relationship studies. Drug combination and novel type of drug-targeted delivery system thereof have been well developed. This article is ended by a perspective remark of futuristic development of natural product-based therapeutic regimen for liver cancer treatment. We expect that this review is an account for current status of natural products as promising anti-liver cancer treatments and should contribute to its understanding.


Asunto(s)
Antineoplásicos/uso terapéutico , Productos Biológicos/uso terapéutico , Neoplasias Hepáticas/tratamiento farmacológico , Sorafenib/uso terapéutico , Flavonoides/farmacología , Flavonoides/uso terapéutico , Ginsenósidos/uso terapéutico , Humanos , Proteínas Inmediatas-Precoces/antagonistas & inhibidores , Proteínas Inmediatas-Precoces/metabolismo , Neoplasias Hepáticas/patología , Células Madre Neoplásicas/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/metabolismo , Resveratrol/uso terapéutico
10.
Nano Res ; 14(9): 3033-3050, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33841746

RESUMEN

Laser-assisted process can enable facile, mask-free, large-area, inexpensive, customizable, and miniaturized patterning of laser-induced porous graphene (LIG) on versatile carbonaceous substrates (e.g., polymers, wood, food, textiles) in a programmed manner at ambient conditions. Together with high tailorability of its porosity, morphology, composition, and electrical conductivity, LIG can find wide applications in emerging bioelectronics (e.g., biophysical and biochemical sensing) and soft robots (e.g., soft actuators). In this review paper, we first introduce the methods to make LIG on various carbonaceous substrates and then discuss its electrical, mechanical, and antibacterial properties and biocompatibility that are critical for applications in bioelectronics and soft robots. Next, we overview the recent studies of LIG-based biophysical (e.g., strain, pressure, temperature, hydration, humidity, electrophysiological) sensors and biochemical (e.g., gases, electrolytes, metabolites, pathogens, nucleic acids, immunology) sensors. The applications of LIG in flexible energy generators and photodetectors are also introduced. In addition, LIG-enabled soft actuators that can respond to chemicals, electricity, and light stimulus are overviewed. Finally, we briefly discuss the future challenges and opportunities of LIG fabrications and applications.

11.
J Urol ; 204(6): 1347-1348, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32993449
12.
Proc Natl Acad Sci U S A ; 117(31): 18292-18301, 2020 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-32661158

RESUMEN

Pencils and papers are ubiquitous in our society and have been widely used for writing and drawing, because they are easy to use, low-cost, widely accessible, and disposable. However, their applications in emerging skin-interfaced health monitoring and interventions are still not well explored. Herein, we report a variety of pencil-paper-based on-skin electronic devices, including biophysical (temperature, biopotential) sensors, sweat biochemical (pH, uric acid, glucose) sensors, thermal stimulators, and humidity energy harvesters. Among these devices, pencil-drawn graphite patterns (or combined with other compounds) serve as conductive traces and sensing electrodes, and office-copy papers work as flexible supporting substrates. The enabled devices can perform real-time, continuous, and high-fidelity monitoring of a range of vital biophysical and biochemical signals from human bodies, including skin temperatures, electrocardiograms, electromyograms, alpha, beta, and theta rhythms, instantaneous heart rates, respiratory rates, and sweat pH, uric acid, and glucose, as well as deliver programmed thermal stimulations. Notably, the qualities of recorded signals are comparable to those measured with conventional methods. Moreover, humidity energy harvesters are prepared by creating a gradient distribution of oxygen-containing groups on office-copy papers between pencil-drawn electrodes. One single-unit device (0.87 cm2) can generate a sustained voltage of up to 480 mV for over 2 h from ambient humidity. Furthermore, a self-powered on-skin iontophoretic transdermal drug-delivery system is developed as an on-skin chemical intervention example. In addition, pencil-paper-based antennas, two-dimensional (2D) and three-dimensional (3D) circuits with light-emitting diodes (LEDs) and batteries, reconfigurable assembly and biodegradable electronics (based on water-soluble papers) are explored.


Asunto(s)
Electrónica/instrumentación , Grafito , Monitoreo Fisiológico/instrumentación , Piel , Dispositivos Electrónicos Vestibles , Suministros de Energía Eléctrica , Electrodos , Diseño de Equipo , Humanos , Papel
13.
J Urol ; 204(6): 1341-1348, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32718276

RESUMEN

PURPOSE: Surgery is the first line treatment for congenital concealed penis but penile retraction is inevitable in some cases. We investigate the anatomical and histological characteristics of penile fasciae and describe a new technique for the correction of concealed penis. MATERIALS AND METHODS: The anatomical structures of penile fasciae were observed in 10 adult cadaveric penises. Penile tissue samples were stained with hematoxylin-eosin, Masson's trichrome and Weigert's resorcin-fuchsin, respectively. From January 2017 to May 2019, 78 patients with congenital concealed penis were treated with the new surgical technique. Median patient age was 14 years (range 8 to 18). RESULTS: Dartos fascia had sublayers. The superficial layer was a well vascularized tissue composed of nonpolar collagen fibers intermixed with nerves and vessels. The deep layer was composed of a transverse arrangement of collagen fibers and elastic fibers, and there were fewer venules and nerve fibers. Based on this finding we performed anatomical resection of the deep layer of dartos fascia to correct concealed penis. During the operation dartos fascia was separated into 2 layers and a complete circular resection of the deep layer was made at the base of the penis. Mean followup was 14 months. All patients and their parents were satisfied with the outcomes. None of the patients underwent postoperative penile retraction. CONCLUSIONS: The anatomical resection of the deep layer of dartos fascia for correcting concealed penis is technically easy, safe and effective. It provides a good cosmetic appearance and functional outcomes.


Asunto(s)
Fascia/patología , Fasciotomía/métodos , Enfermedades de los Genitales Masculinos/cirugía , Pene/anomalías , Procedimientos Quirúrgicos Urológicos Masculinos/métodos , Adolescente , Adulto , Cadáver , Niño , Fasciotomía/efectos adversos , Estudios de Factibilidad , Estudios de Seguimiento , Enfermedades de los Genitales Masculinos/congénito , Enfermedades de los Genitales Masculinos/patología , Humanos , Masculino , Pene/patología , Pene/cirugía , Resultado del Tratamiento , Procedimientos Quirúrgicos Urológicos Masculinos/efectos adversos
14.
Adv Mater ; 32(17): e1908475, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32173920

RESUMEN

Mechanically guided, 3D assembly has attracted broad interests, owing to its compatibility with planar fabrication techniques and applicability to a diversity of geometries and length scales. Its further development requires the capability of on-demand reversible shape reconfigurations, desirable for many emerging applications (e.g., responsive metamaterials, soft robotics). Here, the design, fabrication, and modeling of soft electrothermal actuators based on laser-induced graphene (LIG) are reported and their applications in mechanically guided 3D assembly and human-soft actuators interaction are explored. Over 20 complex 3D architectures are fabricated, including reconfigurable structures that can reshape among three distinct geometries. Also, the structures capable of maintaining 3D shapes at room temperature without the need for any actuation are realized by fabricating LIG actuators at an elevated temperature. Finite element analysis can quantitatively capture key aspects that govern electrothermally controlled shape transformations, thereby providing a reliable tool for rapid design optimization. Furthermore, their applications are explored in human-soft actuators interaction, including elastic metamaterials with human gesture-controlled bandgap behaviors and soft robotic fingers which can measure electrocardiogram from humans in an on-demand fashion. Other demonstrations include artificial muscles, which can lift masses that are about 110 times of their weights and biomimetic frog tongues which can prey insects.


Asunto(s)
Grafito/química , Láseres de Gas , Robótica , Biomimética , Electromiografía , Dedos/fisiología , Análisis de Elementos Finitos , Humanos , Músculos/fisiología , Temperatura , Dispositivos Electrónicos Vestibles
15.
Nanomicro Lett ; 12(1): 16, 2020 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-34138066

RESUMEN

Carbon quantum dots (CQDs) as a new class of emerging materials have gradually drawn researchers' concern in recent years. In this work, the graphitic CQDs are prepared through a scalable approach, achieving a high yield with more than 50%. The obtained CQDs are further used as structure-directing and conductive agents to synthesize novel N,S-CQDs/NiCo2S4 composite cathode materials, manifesting the enhanced electrochemical properties resulted from the synergistic effect of highly conductive N,S-codoped CQDs offering fast electronic transport and unique micro-/nanostructured NiCo2S4 microspheres with Faradaic redox characteristic contributing large capacity. Moreover, the nitrogen-doped reduced graphene oxide (N-rGO)/Fe2O3 composite anode materials exhibit ultrahigh specific capacity as well as significantly improved rate property and cycle performance originating from the high-capacity prism-like Fe2O3 hexahedrons tightly wrapped by highly conductive N-rGO. A novel alkaline aqueous battery assembled by these materials displays a specific energy (50.2 Wh kg-1), ultrahigh specific power (9.7 kW kg-1) and excellent cycling performance with 91.5% of capacity retention at 3 A g-1 for 5000 cycles. The present research offers a valuable guidance for the exploitation of advanced energy storage devices by the rational design and selection of battery/capacitive composite materials.

16.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(5): 419-424, 2019 May.
Artículo en Chino | MEDLINE | ID: mdl-31223111

RESUMEN

Objective To investigate the effects of leucine-rich pentatricopeptide repeat containing (LRPPRC) on proliferation and apoptosis in hormone resistant prostate cancer cells. Methods LRPPRC and androgen receptor (AR) expressions in DU145 and LNCaP cells were detected by Western blot analysis. The siRNA targeting LRPPRC gene was transiently transfected into DU145 cells. LRPPRC expression was detected by reverse transcription PCR and Western blot analysis. The cell survival rate was analyzed by MTT assay. ATP was measured by luciferin-luciferase assay. The cell apoptosis was investigated by flow cytometry and Hoechst 33258 staining. Caspase-3, Bcl2 and BAX protein expressions were detected by Western blot analysis. Results DU145 and LNCaP cells highly expressed LRPPRC. LNCaP cells highly expressed AR, while no expression of AR was observed in DU145 cells. Down-regulation of LRPPRC decreased cell survival rate and ATP level, increased apoptosis rate and caspase-3 activation, and decreased Bcl2 expression in DU145 cells. Conclusion Knock-down of LRPPRC promotes apoptosis of hormone resistant prostate cancer cells.


Asunto(s)
Apoptosis , Proteínas de Neoplasias/genética , Neoplasias de la Próstata/patología , Caspasa 3/metabolismo , Línea Celular Tumoral , Proliferación Celular , Regulación hacia Abajo , Técnicas de Silenciamiento del Gen , Humanos , Masculino , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Receptores Androgénicos/metabolismo
17.
Inorg Chem ; 58(9): 6410-6421, 2019 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-31009210

RESUMEN

Given its competitive theoretical capacity, Bi2MoO6 is deemed as a promising anode material for the realization of efficient Li storage. Considering the severe capacity attenuation caused by the lithiation-induced expansion, it is essential to introduce effective modification. Remarkably, in this work, Bi2MoO6 microsphere with double-layered spherical shells are successfully prepared, and the polyaniline are coated on both inner and outer surfaces of double-layered spherical shells, working as buffer layers to strain the volume expansion during electrochemical cycling. Inspiringly, when utilized as anode in LIBs, the specific capacity of Bi2MoO6@PANI is maintained at 656.3 mAh g-1 after 200 cycles at 100 mA g-1, corresponding to a high capacity of 82%. However, the counterpart of individual Bi2MoO6 is only 36%. This result confirms that the polyaniline layer can dramatically promote stable cycling performances. Supported by in situ EIS and ex situ technologies followed by detailed analysis, the enhanced pseudocapacitance-dominated contributions and electron/ion transfer rate, benefiting from the combination with polyaniline, are further proved. This work confirms the significant effect of polyaniline on the ultrastable energy storage, further providing an in-depth sight on the impacts of polyaniline coating to the electrical conductivity as well as the resistances of electron/ion transport.

18.
ACS Appl Mater Interfaces ; 11(6): 6154-6165, 2019 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-30645091

RESUMEN

Compared to chemosynthetic CuFeS2, natural chalcopyrite (CuFeS2) can be regarded as a promising anode material for exploring ultrafast and stable Li-ion batteries benefiting from it being firsthand, eco-friendly, and resource-rich. Considering the nonuniform size distribution in it and the fact that homogeneous grain distributions can effectively restrain the aggregation of active materials, the engineering of size is deemed an effective strategy to achieve excellent Li-storage performances. Herein, varisized natural CuFeS2 are obtained by facial mineral processing technology and outstanding Li-storage performances are exhibited. Along with the decreasing of size, the contribution of pseudocapacitive as well as the ion transfer rates are significantly boosted. As expected, even at 1 A g-1, a remarkable capacity of 1009.7 mA h g-1 is displayed by the sample with the smallest size and most uniform distributions even after 500 cycles. Furthermore, supported by the detailed analysis of in situ X-ray diffraction and kinetic features, a hybrid of multiple lithium-metal sulfur systems and the major origin of the enhanced capacity upon long cycles are confirmed. Remarkably, this work is expected to increase the far-ranging applications of natural chalcopyrite as a firsthand anode material for lithium-ion batteries (LIBs) and inform the readers about the effects of particle size on Li-storage performances.

19.
Adv Sci (Weinh) ; 5(6): 1800080, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29938187

RESUMEN

Different dimensions of carbon materials with various features have captured numerous interests due to their applications on the tremendous fields. Restricted by the raw materials and devices, the controlling of their morphology is a major challenge. Utilizing the catalytic features of the intermediates from the low-cost salts and polymerization of 0D carbon quantum dots (CQDs), 0D CQDs are expected to self-assemble into 1/2/3D carbon structures with the assistance of temperature-induced intermediates (e.g., ZnO, Ni, and Cu) from the salts (ZnCl2, NiCl2, and CuCl). The formation mechanisms are illustrated as follows: 1) the "orient induction" to evoke "vine style" growth mechanism of ZnO; 2) the "dissolution-precipitation" of Ni; and 3) the "surface adsorption self-limited" of Cu. Subsequently, the degree of graphitization, interlayer distance, and special surface area are investigated in detail. 1D structure from 700 °C as anode displays a high Na-storage capacity of 301.2 mAh g-1 at 0.1 A g-1 after 200 cycles and 107 mAh g-1 at 5.0 A g-1 after 5000 cycles. Quantitative kinetics analysis confirms the fundamentals of the enhanced rate capacity and the potential region of Na-insertion/extraction. This elaborate work opens up an avenue toward the design of carbon with multidimensions and in-depth understanding of their sodium-storage features.

20.
Dalton Trans ; 47(7): 2256-2265, 2018 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-29363697

RESUMEN

Various V2O5 three-dimensional nanostructures are synthesized using a facile template-free hydrothermal method and evaluated for use as supercapacitor electrode materials. As a result, the yolk-shell structure assembled from ultrathin nanosheets shows the best electrochemical performance, with a specific capacitance of 704.17 F g-1 at 1.0 A g-1 and a high capacity retention of 89% over 4000 cycles at 3.0 A g-1. In addition, a continuous three-dimensional porous coralline-shaped carbon is synthesized from osmanthus and has a large Brunauer-Emmett-Teller surface area of 2840.88 m2 g-1. Then, an asymmetric supercapacitor is developed using the as-prepared yolk-shell V2O5 as a positive electrode and the osmanthus derived coralline-shaped carbon as a negative electrode. This exhibits an energy density of 29.49 W h kg-1 at a power density of 800 W kg-1 with a good cycling performance that retains 90.6% of its initial capacity after 2000 cycles at 3.0 A g-1. Furthermore, two cells in series can easily brightly light up a light-emitting diode (3 V), further demonstrating the great potential of the prepared materials for high-performance supercapacitor devices.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA