Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nanomicro Lett ; 14(1): 113, 2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35482108

RESUMO

Metal-organic framework-templated nitrogen-doped graphitic carbon (NGC) and polydopamine-derived carbon (PDA-derived C)-double coated one-dimensional CoSe2 nanorods supported highly porous three-dimensional microspheres are introduced as anodes for excellent Na-ion batteries, particularly with long-lived cycle under carbonate-based electrolyte system. The microspheres uniformly composed of ZIF-67 polyhedrons and polystyrene nanobeads (ϕ = 40 nm) are synthesized using the facile spray pyrolysis technique, followed by the selenization process (P-CoSe2@NGC NR). Further, the PDA-derived C-coated microspheres are obtained using a solution-based coating approach and the subsequent carbonization process (P-CoSe2@PDA-C NR). The rational synthesis approach benefited from the synergistic effects of dual carbon coating, resulting in a highly conductive and porous nanostructure that could facilitate rapid diffusion of charge species along with efficient electrolyte infiltration and effectively channelize the volume stress. Consequently, the prepared nanostructure exhibits extraordinary electrochemical performance, particularly the ultra-long cycle life stability. For instance, the advanced anode has a discharge capacity of 291 (1000th cycle, average capacity decay of 0.017%) and 142 mAh g-1 (5000th cycle, average capacity decay of 0.011%) at a current density of 0.5 and 2.0 A g-1, respectively.

2.
Small Methods ; 5(9): e2100195, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34928059

RESUMO

Highly conductive 3D ordered mesoporous Ni7 S6 -MoS2 /N-doped graphitic carbon (NGC) composite (P-NiMoS/C) microspheres are prepared as anode materials for Na-ion batteries. The rationally designed nanostructure comprises stable Ni7 S6 - and MoS2 -phases along with the homogeneously distributed ordered mesopores (ϕ = 50 nm) over the external and internal structures generated through thermal decomposition of polystyrene nanobeads (ϕ = 100 nm). Therefore, the P-NiMoS/C microspheres deliver initial discharge capacities of 662, 419, 373, 300, 231, 181, and 146 mA h g-1 at current densities of 0.5, 1, 2, 4, 6, 8, and 10 A g-1 , respectively. Furthermore, P-NiMoS/C exhibits a stable discharge capacity of 444 mA h g-1 at the end of the 150th cycle at a current density of 0.5 A g-1 , indicating higher cycling stability than the filled, that is, non-mesoporous, Ni3 S2 -MoS2 /NGC (F-NiMoS/C) microspheres and filled carbon-free Ni3 S2 -MoS2 (F-NiMoS) microspheres. The superior electrochemical performance of P-NiMoS/C microspheres is attributed to the rapid Na+ ion diffusion, alleviation of severe volume stress during prolonged cycling, and higher electrical conductivity of NGC, which results in fast charge transfer during the redox processes. The results in the present study can provide fundamental knowledge for the development of multicomponent, porous, and highly conductive anodes for various applications.

3.
Small ; 16(38): e2003391, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32830418

RESUMO

Golden bristlegrass-like unique nanostructures comprising reduced graphene oxide (rGO) matrixed nanofibers entangled with bamboo-like N-doped carbon nanotubes (CNTs) containing CoSe2 nanocrystals at each node (denoted as N-CNT/rGO/CoSe2 NF) are designed as anodes for high-rate sodium-ion batteries (SIBs). Bamboo-like N-doped CNTs (N-CNTs) are successfully generated on the rGO matrixed nanofiber surface, between rGO sheets and mesopores, and interconnected chemically with homogeneously distributed rGO sheets. The defects in the N-CNTs formed by a simple etching process allow the complete phase conversion of Co into CoSe2 through the efficient penetration of H2 Se gas inside the CNT walls. The N-CNTs bridge the vertical defects for electron transfer in the rGO sheet layers and increase the distance between the rGO sheets during cycles. The discharge capacity of N-CNT/rGO/CoSe2 NF after the 10 000th cycle at an extremely high current density of 10 A g-1 is 264 mA h g-1 , and the capacity retention measured at the 100th cycle is 89%. N-CNT/rGO/CoSe2 NF has final discharge capacities of 395, 363, 328, 304, 283, 263, 246, 223, 197, 171, and 151 mA h g-1 at current densities of 1, 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20 A g-1 , respectively.

4.
Small ; 16(32): e2002213, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32614514

RESUMO

Hierarchically well-developed porous graphene nanofibers comprising N-doped graphitic C (NGC)-coated cobalt oxide hollow nanospheres are introduced as anodes for high-rate Li-ion batteries. For this, three strategies, comprising the Kirkendall effect, metal-organic frameworks, and compositing with highly conductive C, are applied to the 1D architecture. In particular, NGC layers are coated on cobalt oxide hollow nanospheres as a primary transport path of electrons followed by graphene-nanonetwork-constituting nanofibers as a continuous and secondary electron transport path. Superior cycling performance is achieved, as the unique nanostructure delivers a discharge capacity of 823 mAh g-1 after 500 cycles at 3.0 A g-1 with a low decay rate of 0.092% per cycle. The rate capability is also noteworthy as the structure exhibits high discharge capacities of 1035, 929, 847, 787, 747, 703, 672, 650, 625, 610, 570, 537, 475, 422, 294, and 222 mAh g-1 at current densities of 0.5, 1.5, 3, 5, 7, 10, 12, 15, 18, 20, 25, 30, 40, 50, 80, and 100 A g-1 , respectively. In view of the highly efficient Li+ ion/electron diffusion and high structural stability, the present nanostructuring strategy has a huge potential in opening new frontiers for high-rate and long-lived stable energy storage systems.

5.
Immune Netw ; 19(5): e36, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31720047

RESUMO

Mesenchymal stem cells (MSCs) ameliorate the renal injury in Adriamycin (ADR)-induced nephropathy, but the mechanisms underlying their efficacy remain incompletely understood. In this study, we demonstrated that MSCs increased the survival, recovered body weight loss, and decreased proteinuria and serum creatinine levels in ADR-treated mice. MSCs also prevented podocyte damage and renal fibrosis by decreasing the expression of fibronectin, collagen 1α1, and α-smooth muscle actin. From a mechanistic perspective, MSCs inhibited renal inflammation by lowering the expression of CCL4, CCL7, CCL19, IFN-α/ß, TGF-ß, TNF-α, and chitinase 3-like 1. In summary, our data demonstrate that MSCs improve renal functions by inhibiting renal inflammation in ADR-induced nephropathy.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...