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conferenceseries
.com
Volume 9
Journalof Nanomedicine&Nanotechnology
Asia Pacific Nano Congress 2018
August 10-11, 2018
August 10-11, 2018 Osaka, Japan
2
nd
World Congress on
Nanoscience and Nanotechnology
Enhanced catalytic activity of MoS
2
nanoclusters for the hydrogen evolution reaction by Ni-doping
and sulfur enrichment
Yubiao Niu
1
, Richard E Palmer
1
, Daniel Escalera-López
2
and Neil V Rees
2
1
Swansea University Bay Campus, UK
2
University of Birmingham, UK
T
he discovery of highly active and low-cost electrochemical catalysts is a crucial challenge for the development of
efficient hydrogen technologies. Molybdenum disulfide (MoS
2
) is an earth-abundant material and considered as a
promising candidate for electrocatalytic applications such as the Hydrogen Evolution Reaction (HER). DFT calculations have
demonstrated that transition metal (Fe, Co, Ni) doping of MoS
2
should increase the activity in the HER. Here we report a novel
one-step strategy for the preparation of Ni-doped transition metal-MoS
2-x
hybrid clusters based on dual-target magnetron
sputtering and gas condensation. The structure and composition of the clusters are analyzed by aberration-corrected Scanning
Transmission Electron Microscope (STEM) in High-Angle Annular Dark Field (HAADF) mode coupled with EDX. From
the electrochemical measurements, the Ni-MoS
2-x
nanoclusters display a favorable 100 mV shift in the HER onset potential
and an almost 3-fold increase in exchange current density compared with undoped MoS
2
clusters. It is believed that sulfur
atoms at the edge sites of the MoS
2
layers make the main contribution to the HER catalytic activity. Thus we have also explored
sulfur-enrichment of (mass-selected) MoS
2-x
clusters via sulfur evaporation and cluster annealing under vacuum conditions.
Sulfur addition leads to MoS
2+x
clusters with well-developed crystalline structure instead of poorly ordered layer structures
and significantly enhances the activity in the HER, with 200 mV shifts to lower HER onset potentials and more than 30-fold
increase in exchange current density.
Recent Publications
1. D Escalera-López, Y Niu, S Park, M Isaacs, K Wilson, R E Palmer, N V Rees (2018) Hydrogen evolution enhancement of
ultra-low loading, size-selectedmolybdenumsulfide nanoclusters by sulfur enrichment.
AppliedCatalysis B: Environmental;
235: 84-91.
2. Y Niu, P Schlexer, B Sebok, I Chorkendorff, G Pacchioni, R E Palmer (2018) Reduced Sintering of Mass-selected Au
Clusters on SiO2 by Alloying with Ti: An Aberration-corrected STEM and Computational Study.
Nanoscale
; 10: 2363-2370.
Biography
Yubiao Niu is a Research Officer in Nanomaterials Lab of Swansea University. His research interest focuses on the development of innovative nanomaterials
from earth-abundant materials for heterogeneous catalysis to alleviate the problems with the availability of precious metals as catalyst including the fabrication of
nanomaterials, the fundamental studies of nanostructures and the catalytic measurements. He has expertise in nanocluster fabrication with cluster beam source
and (aberration-corrected) Scanning Transmission Electron Microscopy (STEM) together with Energy Dispersive X-ray (EDX) spectroscopy and Electron Energy
Loss Spectroscopy (EELS).
yubiao.niu@swansea.ac.ukYubiao Niu et al., J Nanomed Nanotechnol 2018, Volume 9
DOI: 10.4172/2157-7439-C6-082