Enhancement of the hydrogen evolution reaction from Ni-MoS2 hybrid nanoclusters

Research output: Contribution to journalArticlepeer-review

Authors

  • Daniel Escalera López
  • Yubiao Niu
  • Kevin Cooke

Colleges, School and Institutes

External organisations

  • Teer Coatings Ltd

Abstract

This report focuses on a novel strategy for the preparation of transition metal-MoS2 hybrid 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 MoS2 in the hybrid nanoclusters (average diameter = 5.0 nm, Mo:S ratio = 1:1.8 ± 0.1). The Ni-MoS2 nanoclusters 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 undated MoS2 nanoclusters, the latter effect in agreement with reported DFT calculations. This activity is only reached after air exposure of the Ni-MoS2 hybrid 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 voltammeter (ASV) experiments on the Ni-MoS2 hybrid 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.

Details

Original languageEnglish
Pages (from-to)6008-6017
Number of pages10
JournalACS Catalysis
Volume6
Issue number9
Early online date2 Aug 2016
Publication statusPublished - 2 Sep 2016

Keywords

  • doping, hydrogen evolution, magnetron sputtering deposition, molybdenum disulfide, nanoclusters, STEM