Enhancement of the Hydrogen Evolution Reaction from Ni-MoS2Hybrid Nanoclusters.
This report focuses on a novel strategy for the preparation of transition metal-MoS2hybrid nanoclusters based on a one-step, dual-target magnetron sputtering, and gas condensation process demonstrated for Ni-MoS2. Aberration-corrected STEM images coupled with EDX analysis confirms the presence of Ni and MoS2in the hybrid nanoclusters (average diameter = 5.0 nm, Mo:S ratio = 1:1.8 ± 0.1). The Ni-MoS2nanoclusters display a 100 mV shift in the hydrogen evolution reaction (HER) onset potential and an almost 3-fold increase in exchange current density compared with the undoped MoS2nanoclusters, the latter effect in agreement with reported DFT calculations. This activity is only reached after air exposure of the Ni-MoS2hybrid nanoclusters, suggested by XPS measurements to originate from a Ni dopant atoms oxidation state conversion from metallic to 2+ characteristic of the NiO species active to the HER. Anodic stripping voltammetry (ASV) experiments on the Ni-MoS2hybrid nanoclusters confirm the presence of Ni-doped edge sites and reveal distinctive electrochemical features associated with both doped Mo-edge and doped S-edge sites which correlate with both their thermodynamic stability and relative abundance.
Centre for Hydrogen and Fuel Cell Research, School of Chemical Engineering, University of Birmingham, Birmingham B15 2TT, United Kindgom; Nanoscale Physics Research Laboratory, School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, United Kindgom.
Daniel
D
Escalera-López
Nanoscale Physics Research Laboratory, School of Physics and Astronomy, University of Birmingham , Birmingham B15 2TT, United Kindgom.
Yubiao
Y
Niu
Teer Coatings Ltd., Berry Hill Industrial Estate, Droitwich, Worcestershire WR9 9AS, United Kindgom.
Jinlong
J
Yin
Teer Coatings Ltd., Berry Hill Industrial Estate, Droitwich, Worcestershire WR9 9AS, United Kindgom.
Kevin
K
Cooke
Centre for Hydrogen and Fuel Cell Research, School of Chemical Engineering, University of Birmingham , Birmingham B15 2TT, United Kindgom.
Neil V
NV
Rees
Nanoscale Physics Research Laboratory, School of Physics and Astronomy, University of Birmingham , Birmingham B15 2TT, United Kindgom.
Richard E
RE
Palmer
STEM; doping; hydrogen evolution; magnetron sputtering deposition; molybdenum disulfide; nanoclusters