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










Base de dados
Intervalo de ano de publicação
1.
Phys Chem Chem Phys ; 22(2): 430-436, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31675033

RESUMO

Hydrogen energy is a high-efficiency and clean energy, but the problem of storage still prevents its extensive use. Large-surface-area, two-dimensional (2D) layered materials have an advantage in hydrogen storage applications. Monolayer MoS2 is a typical 2D material that has been widely studied recently. And the 1T' phase of MoS2 is a focus especially for studies concerning hydrogen. Here, first-principles calculations are carried out to investigate the adsorption behaviors of hydrogen molecules on 1T' MoS2. Comparing with other MoS2-based materials, such as doped or decorated 2H-MoS2, 1T' MoS2 has even better performance in hydrogen adsorption, and its preparation is easier. In multiple hydrogen molecule adsorption, the material shows good stability and appropriate adsorption energy while adsorbing hydrogen molecules. With the researches in this paper, the connection between the adsorption energy and hydrogen mass fraction was set up. This can provide a reference for further studies on hydrogen storage applications.

2.
ACS Appl Mater Interfaces ; 10(2): 1752-1760, 2018 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-29271634

RESUMO

When using water splitting to achieve sustainable hydrogen production, low-cost, stable, and naturally abundant electrocatalysts are required to replace Pt-based ones for the hydrogen evolution reaction (HER). Herein, for the first time, a novel nanostructure with one-dimensional (1D) MoS2/Ni3S2 nanoarrays directly grow on a three-dimensional (3D) Ni foam is developed for this purpose, showing excellent catalytic activity and stability. The as-prepared 3D MoS2/Ni3S2/Ni composite has an onset overpotential as low as 13 mV in 1 M KOH, which is comparable to Pt-based electrocatalyst for HER. According to the classical theory, the Tafel slope of the new composite is relatively low, as it goes through a combined Volmer-Heyrovsky mechanism during hydrogen evolution. All the results attribute the excellent electrocatalytic activity of the nanostructure to the electrical coupling among Ni, Ni3S2, and MoS2, the super hydrophilic interface, the synergistic catalytic effects produced by the MoS2/Ni3S2 nanoarrays, and abundant exposed active edge sites. These unique and previously undeveloped characteristics of the 3D MoS2/Ni3S2/Ni composite make it a very promising earth-abundant electrocatalyst for HER.

3.
Sci Rep ; 7(1): 8825, 2017 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-28821779

RESUMO

Unique hybrid nanostructure, which consists of multi-wall carbon nanotube (MWCNT) stems and MoS2 nanosheet (NS) leaves, are prepared by a hydrothermal method. The fabricated material can be potentially used as an electrocatalyst for the hydrogen evolution reaction (HER). To our knowledge, as the reaction medium, water is firstly utilized to the synthesis of the 1T phase MoS2 NSs which uniformly grow on the carbon-based materials. As a result, a nanohybrid catalyst with excellent HER electrocatalytic properties, which included an onset potential of as low as 50 mV, a Tafel slope of 43 mV dec-1, and remarkable cycling stability, is produced. The observed outstanding catalytic performance can be attributed to the uniform distribution of the metallic 1T phase of the MoS2 NSs, which are characterized by the presence of multiple active edges as well as the effective electron transport route provided by the conductive MWCNT substrate. This work demonstrates the high potential of the synthesized HER catalyst and proposes a novel, efficient, environmentally friendly, and inexpensive method for its fabrication.

4.
PLoS One ; 12(5): e0177258, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28481951

RESUMO

Molybdenum disulfide nanosheets/reduced graphene oxide (MoS2 NSs/rGO) nanohybrid as a highly effective catalyst for hydrogen evolution reaction (HER) have been successfully synthesized by a facile microwave-assisted method. The results clearly reveal that direct grown of MoS2 NSs on rGO have been achieved. Electrochemical tests show that the as-prepared hybrid material exhibited excellent HER activity, with a small Tafel slope of 57 mV dec-1, an overpotential of 130 mV and remarkable cycling stability. After analysis, the observed outstanding catalytic performance can be attributed to the uniform distribution of the MoS2 NSs, which are characterized by the presence of multiple active sites as well as the effective electron transport route provided by the conductive rGO substrate. Moreover, according to the classic theory, the mechanism governing of the catalytic HER on the MoS2 NSs/rGO nanohybrid has been clarified.


Assuntos
Dissulfetos/química , Técnicas Eletroquímicas/métodos , Grafite/química , Hidrogênio/química , Molibdênio/química , Óxidos/química , Catálise , Microscopia Eletrônica de Transmissão , Difração de Raios X
5.
PLoS One ; 11(8): e0161374, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27556402

RESUMO

Advanced approaches to preparing non-noble-metal electrocatalysts for the hydrogen evolution reaction (HER) are considered to be a significant breakthrough in promoting the exploration of renewable resources. In this work, a hybrid material of MoS2 nanoflowers (NFs) on reduced graphene oxide (rGO) was synthesized as a HER catalyst via an environmentally friendly, efficient approach that is also suitable for mass production. Small-sized MoS2 NFs with a diameter of ca. 190 nm and an abundance of exposed edges were prepared by a hydrothermal method and were subsequently supported on rGO by microwave-assisted synthesis. The results show that MoS2 NFs were distributed uniformly on the remarkably reduced GO and preserved the outstanding original structural features perfectly. Electrochemical tests show that the as-prepared hybrid material exhibited excellent HER activity, with a small Tafel slope of 80 mV/decade and a low overpotential of 170 mV.


Assuntos
Dissulfetos/química , Técnicas Eletroquímicas , Grafite/química , Hidrogênio/química , Micro-Ondas , Molibdênio/química , Nanoestruturas/química , Catálise , Nanoestruturas/ultraestrutura , Óxidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA