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Hierarchical Ni-Mo-S nanosheets on carbon fiber cloth: A flexible electrode for efficient hydrogen generation in neutral electrolyte.

Miao J, Xiao FX, Yang HB, Khoo SY, Chen J, Fan Z, Hsu YY, Chen HM, Zhang H, Liu B - Sci Adv (2015)

Bottom Line: The incorporation of Ni atoms in Mo-S plays a crucial role in tuning its intrinsic catalytic property by creating substantial defect sites as well as modifying the morphology of Ni-Mo-S network at atomic scale, resulting in an impressive enhancement in the catalytic activity.Furthermore, the Ni-Mo-S/C electrode has excellent electrocatalytic stability over an extended period, much better than those of MoS2/C and Pt plate electrodes.The intuitive comparison test was designed to reveal the superior gas-evolving profile of Ni-Mo-S/C over that of MoS2/C, and a laboratory-scale hydrogen generator was further assembled to demonstrate its potential application in practical appliances.

View Article: PubMed Central - PubMed

Affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore.

ABSTRACT
A unique functional electrode made of hierarchal Ni-Mo-S nanosheets with abundant exposed edges anchored on conductive and flexible carbon fiber cloth, referred to as Ni-Mo-S/C, has been developed through a facile biomolecule-assisted hydrothermal method. The incorporation of Ni atoms in Mo-S plays a crucial role in tuning its intrinsic catalytic property by creating substantial defect sites as well as modifying the morphology of Ni-Mo-S network at atomic scale, resulting in an impressive enhancement in the catalytic activity. The Ni-Mo-S/C electrode exhibits a large cathodic current and a low onset potential for hydrogen evolution reaction in neutral electrolyte (pH ~7), for example, current density of 10 mA/cm(2) at a very small overpotential of 200 mV. Furthermore, the Ni-Mo-S/C electrode has excellent electrocatalytic stability over an extended period, much better than those of MoS2/C and Pt plate electrodes. Scanning and transmission electron microscopy, Raman spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and x-ray absorption spectroscopy were used to understand the formation process and electrocatalytic properties of Ni-Mo-S/C. The intuitive comparison test was designed to reveal the superior gas-evolving profile of Ni-Mo-S/C over that of MoS2/C, and a laboratory-scale hydrogen generator was further assembled to demonstrate its potential application in practical appliances.

No MeSH data available.


Raman spectroscopy.Raman spectra of Ni-Mo-S/C (1:1) and MoS2/C. Inset: Schematic illustration of  and A1g vibrational modes in layered 2H-MoS2.
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Figure 6: Raman spectroscopy.Raman spectra of Ni-Mo-S/C (1:1) and MoS2/C. Inset: Schematic illustration of and A1g vibrational modes in layered 2H-MoS2.

Mentions: Figure 6 shows the Raman spectra of Ni-Mo-S/C (1:1) and MoS2/C. Two distinct peaks at ~380 and ~405 cm−1, corresponding to the in-plane and out-of-plane A1g vibrational modes of 2H-MoS2, can be clearly identified in the spectra of both MoS2/C and Ni-Mo-S/C (1:1) (20, 33, 34). The slightly red shift and broadening of the A1g peak in Ni-Mo-S/C (1:1) can be attributed to reduced numbers of stacked layers along the c axis (33). Besides, the increased width along with reduced intensity of the peak in Ni-Mo-S/C (1:1) reveals the presence of in-plane defect sites (35), which is consistent with our aforementioned experimental observations (Figs. 3 and 4).


Hierarchical Ni-Mo-S nanosheets on carbon fiber cloth: A flexible electrode for efficient hydrogen generation in neutral electrolyte.

Miao J, Xiao FX, Yang HB, Khoo SY, Chen J, Fan Z, Hsu YY, Chen HM, Zhang H, Liu B - Sci Adv (2015)

Raman spectroscopy.Raman spectra of Ni-Mo-S/C (1:1) and MoS2/C. Inset: Schematic illustration of  and A1g vibrational modes in layered 2H-MoS2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643797&req=5

Figure 6: Raman spectroscopy.Raman spectra of Ni-Mo-S/C (1:1) and MoS2/C. Inset: Schematic illustration of and A1g vibrational modes in layered 2H-MoS2.
Mentions: Figure 6 shows the Raman spectra of Ni-Mo-S/C (1:1) and MoS2/C. Two distinct peaks at ~380 and ~405 cm−1, corresponding to the in-plane and out-of-plane A1g vibrational modes of 2H-MoS2, can be clearly identified in the spectra of both MoS2/C and Ni-Mo-S/C (1:1) (20, 33, 34). The slightly red shift and broadening of the A1g peak in Ni-Mo-S/C (1:1) can be attributed to reduced numbers of stacked layers along the c axis (33). Besides, the increased width along with reduced intensity of the peak in Ni-Mo-S/C (1:1) reveals the presence of in-plane defect sites (35), which is consistent with our aforementioned experimental observations (Figs. 3 and 4).

Bottom Line: The incorporation of Ni atoms in Mo-S plays a crucial role in tuning its intrinsic catalytic property by creating substantial defect sites as well as modifying the morphology of Ni-Mo-S network at atomic scale, resulting in an impressive enhancement in the catalytic activity.Furthermore, the Ni-Mo-S/C electrode has excellent electrocatalytic stability over an extended period, much better than those of MoS2/C and Pt plate electrodes.The intuitive comparison test was designed to reveal the superior gas-evolving profile of Ni-Mo-S/C over that of MoS2/C, and a laboratory-scale hydrogen generator was further assembled to demonstrate its potential application in practical appliances.

View Article: PubMed Central - PubMed

Affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore.

ABSTRACT
A unique functional electrode made of hierarchal Ni-Mo-S nanosheets with abundant exposed edges anchored on conductive and flexible carbon fiber cloth, referred to as Ni-Mo-S/C, has been developed through a facile biomolecule-assisted hydrothermal method. The incorporation of Ni atoms in Mo-S plays a crucial role in tuning its intrinsic catalytic property by creating substantial defect sites as well as modifying the morphology of Ni-Mo-S network at atomic scale, resulting in an impressive enhancement in the catalytic activity. The Ni-Mo-S/C electrode exhibits a large cathodic current and a low onset potential for hydrogen evolution reaction in neutral electrolyte (pH ~7), for example, current density of 10 mA/cm(2) at a very small overpotential of 200 mV. Furthermore, the Ni-Mo-S/C electrode has excellent electrocatalytic stability over an extended period, much better than those of MoS2/C and Pt plate electrodes. Scanning and transmission electron microscopy, Raman spectroscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and x-ray absorption spectroscopy were used to understand the formation process and electrocatalytic properties of Ni-Mo-S/C. The intuitive comparison test was designed to reveal the superior gas-evolving profile of Ni-Mo-S/C over that of MoS2/C, and a laboratory-scale hydrogen generator was further assembled to demonstrate its potential application in practical appliances.

No MeSH data available.