W Doping in Ni12P5as a Platform to Enhance Overall Electrochemical Water Splitting

Sirshendu Ghosh, Sunil R. Kadam, Shay Lee Kolatkar, Alevtina Neyman, Chanderpratap Singh, Andrey N. Enyashin, Ronen Bar-Ziv, Maya Bar-Sadan

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Bifunctional electrocatalysts for efficient hydrogen generation from water splitting must overcome both the sluggish water dissociation step of the alkaline hydrogen evolution half-reaction (HER) and the kinetic barrier of the anodic oxygen evolution half-reaction (OER). Nickel phosphides are a promising catalysts family and are known to develop a thin active layer of oxidized Ni in an alkaline medium. Here, Ni12P5 was recognized as a suitable platform for the electrochemical production of γ-NiOOH-a particularly active phase-because of its matching crystallographic structure. The incorporation of tungsten by doping produces additional surface roughness, increases the electrochemical surface area (ESCA), and reduces the energy barrier for electron-coupled water dissociation (the Volmer step for the formation of Hads). When serving as both the anode and cathode, the 15% W-Ni12P5 catalyst provides an overall water splitting current density of 10 mA cm-2 at a cell voltage of only 1.73 V with good durability, making it a promising bifunctional catalyst for practical water electrolysis.

Original languageEnglish
Pages (from-to)581-589
Number of pages9
JournalACS applied materials & interfaces
Volume14
Issue number1
DOIs
StatePublished - 12 Jan 2022

Keywords

  • DFT calculations
  • nickel phosphide
  • oxygen evolution reaction
  • structure-function relationship
  • γ-NiOOH

ASJC Scopus subject areas

  • Materials Science (all)

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