Chemical reduction of porous WO3 and TiO2 photoelectrocatalysts by atomic hydrogen

Juan Miguel Jimenez Morales, Gregor Zickler, Günther Redhammer, Thomas Berger (Corresponding author)

Research output: Contribution to journalArticlepeer-review

Abstract

The donor properties of atomic hydrogen were exploited to chemically reduce nanoparticle-based WO3 and TiO2 electrodes giving rise to a n-type doping of the semiconductors. For this purpose, a reactor system allowing for meticulous materials processing under high vacuum conditions and for the controlled electrode transfer into an aqueous electrolyte was designed and hydrogen doping-induced activity-changes in water photooxidation were studied. The chemical reduction of monoclinic WO3 electrodes leads to increased charge carrier separation at the semiconductor/electrolyte interface. Importantly, the beneficial doping effect is quite stable. However, bronze formation has a negative impact on the photoelectrocatalytic activity of WO3 electrodes upon strong sample reduction. For anatase TiO2 nanoparticle films de-doping of the reduced film is fast due to the small particle size. Correspondingly, the beneficial doping effect is transient. The small particle size allows, however, to estimate the number and energetic distribution of trapped electrons in hydrogen doped films.
Original languageEnglish
JournalApplied Catalysis A: General
Early online date24 Mar 2023
DOIs
Publication statusPublished - 25 May 2023

Fields of Science and Technology Classification 2012

  • 104 Chemistry

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