Catalytic activity and impedance behavior of screen-printed nickel oxide as efficient water oxidation catalysts

Archana Singh, Monika Fekete, Thomas R Gengenbach, Alexandr Simonov, Rosalie Katherine Hocking, Lan-Yun Shery Chang, Mathias Uller Rothmann, Satvasheel Ramesh Powar, Dongchuan Fu, Zheng Hu, Qiang Wu, Yibing Cheng, Udo Bach, Leone Spiccia

Research output: Contribution to journalArticleResearchpeer-review

20 Citations (Scopus)


We report that films screen printed from nickel oxide (NiO) nanoparticles and microballs are efficient electrocatalysts for water oxidation under near-neutral and alkaline conditions. Investigations of the composition and structure of the screen-printed films by X-ray diffraction, X-ray absorption spectroscopy, and scanning electron microscopy confirmed that the material was present as the cubic NiO phase. Comparison of the catalytic activity of the microball films to that of films fabricated by using NiO nanoparticles, under similar experimental conditions, revealed that the microball films outperform nanoparticle films of similar thickness owing to a more porous structure and higher surface area. A thinner, less-resistive NiO nanoparticle film, however, was found to have higher activity per Ni atom. Anodization in borate buffer significantly improved the activity of all three films. X-ray photoelectron spectroscopy showed that during anodization, a mixed nickel oxyhydroxide phase formed on the surface of all films, which could account for the improved activity. Impedance spectroscopy revealed that surface traps contribute significantly to the resistance of the NiO films. On anodization, the trap state resistance of all films was reduced, which led to significant improvements in activity. In 1.00 m NaOH, both the microball and nanoparticle films exhibit high long-term stability and produce a stable current density of approximately 30 mA cm-2 at 600 mV overpotential.
Original languageEnglish
Pages (from-to)4266-4274
Number of pages9
Issue number24
Publication statusPublished - 21 Dec 2015


  • Nanostructures
  • Nickel oxide
  • Screen printing
  • Thin films
  • Water oxidation catalysis

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