MoS2 and WS2 nanocone arrays: Impact of surface topography on the hydrogen evolution electrocatalytic activity and mass transport

Research output: Contribution to journalArticlepeer-review

Authors

  • Daniel Escalera-López
  • Mark Isaacs
  • Karen Wilson
  • Richard E. Palmer

Colleges, School and Institutes

External organisations

  • Aston University
  • School of Science, RMIT University
  • College of Engineering, Swansea University

Abstract

We report the fabrication and electrochemical study of edge-abundant transition metal dichalcogenide (TMD) nanocone arrays. Time-dependent etching by sequential use of isotropic O2 and anisotropic SF6/C4F8 plasmas on nanosphere monolayer-modified TMD crystals results in very high coverage nanocone array structures with tunable aspect ratios and interspacings. Electrochemical characterization of these arrays via the hydrogen evolution reaction (HER), using a low proton concentration electrolyte (2 mM HClO4, 0.1 M NaClO4) to reveal morphology-dependent mass transport features at the proton diffusion-controlled region, show significant changes in electrocatalytic behaviour at both WS2 and MoS2: notably onset potential shifts of 100 and 200 mV, and Tafel slope decreases of 50 and 120 mV dec−1 respectively. These improvements vary according to the geometry of the arrays and the availability of catalytic edge sites, and thus the observed electrochemical behaviour can be rationalized via kinetic and mass transport effects.

Details

Original languageEnglish
Pages (from-to)70-81
Number of pages12
JournalApplied Materials Today
Volume11
Early online date22 Feb 2018
Publication statusPublished - 1 Jun 2018

Keywords

  • Hydrogen evolution, Nanoelectrode array, Plasma etching, Transition metal dichalcogenides

ASJC Scopus subject areas