NiS nanowire arrays doped with vanadium(V) are directly grown on nickel foam by a facile one-step hydrothermal method. It is found that the doping can promote the formation of NiS nanowires at a low temperature. The doped nanowires show excellent electrocatalytic performance toward hydrogen evolution reaction (HER), and outperform pure NiS and other NiS-based compounds. The stability test shows that the performance of V-doped NiS nanowires is improved and stabilized after thousands of linear sweep voltammetry test. The onset potential of V-doped NiS nanowire can be as low as 39 mV, which is comparable to platinum. The nanowire has an overpotential of 68 mV at 10 mA cm, a relatively low Tafel slope of 112 mV dec, good stability and high Faradaic efficiency. First-principles calculations show that the V-doping in NiS extremely enhances the free carrier density near the Fermi level, resulting in much improved catalytic activities. We expect that the doping can be an effective way to enhance the catalytic performance of metal disulfides in hydrogen evolution reaction and V-doped NiS nanowire is one of the most promising electrocatalysts for hydrogen production.
The novel photocatalyst Ti2C/g-C3N4 exhibits substantially enhanced water splitting activities due to its improved light absorbance, efficient separation of photoinduced carriers and large surface area.
Nanostructures have attracted increasing interest for applications in electrolysis of water as electrocatalysts. In this work, the edge-catalytic effects of one dimensional (1D) VS2 nanoribbons with various edge configurations and widths have been investigated based on first-principles calculations. We show that the catalytic ability of VS2 nanoribbons strongly depends on their edge structure, edge configuration, and width. We find that the S-edges of VS2 nanoribbons are more active in electrolysis of water than V-edges due to their optimal Gibbs free energy for hydrogen evolution reaction in a wider range of hydrogen coverages. We also find that narrow nanoribbons show better catalytic performance than their wide counterparts. We further show that the S-edge of narrow VS2 nanoribbons with their V-edge covered by eight sulfur atoms has near-zero Gibbs free energy of hydrogen adsorption and comparable catalytic performance with Pt to a wide range of hydrogen coverage, which is contributed to its metallic characteristic. We expect that VS2 nanoribbons would be a promising 1D catalyst in electrolysis of water because of their impressive catalytic abilities both on the basal planes and edges.
Hydrogen
production via water splitting is considered to be one
of the most promising technologies in the future hydrogen economy,
where the critical challenge in this technology is exploring high-efficient
and cost-effective electrocatalysts. Currently, extensive works from
both experimental and theoretical investigations have shown that two-dimensional
(2D) layered materials can be highly energetic electrocatalysts for
electrically driven hydrogen production. Herein, recent progress in
2D layered materials such as electrocatalysts, including graphene,
graphitic carbon nitride, transitional-metal dichalcogenides, and
MXenes for the hydrogen evolution reaction (HER) will be systematically
discussed and summarized. This review provides a broad overview on
a wide range of strategies to design and fabricate 2D layered materials
as electrocatalysts with high-catalytic performance for HER and aims
to give potential avenues for the design of catalysts for commercial
applications. In addition, the key scientific issues to address the
2D layered materials as HER catalysts are highlighted, and the perspective
on the future development is given at the end.
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