Ag(I) ions working as a hole-transfer mediator in photoelectrocatalytic water oxidation on WO3 film
Author
Monllor-Satoca, Damián
Choi, Wonyong
Park, Hyunwoong
Jeon, Tae Hwa
Moon, Gun–hee
Kim, Wooyul
Kim, Hyoung–il
Bahnemann, Detlef W.
Other authors
Universitat Ramon Llull. IQS
Publication date
2020-02Abstract
Ag(I) is commonly employed as an electron scavenger to promote water oxidation. In addition to its straightforward role as an electron acceptor, Ag(I) can also capture holes to generate the high-valent silver species. Herein, we demonstrate photoelectrocatalytic (PEC) water oxidation and concurrent dioxygen evolution by the silver redox cycle where Ag(I) acts as a hole-transfer mediator. Ag(I) enhances the PEC performance of WO3 electrodes at 1.23 V vs. RHE with increasing O2 evolution, while forming Ag(II) complexes (AgIINO3+). Upon turning off both light and potential bias, the photocurrent immediately drops to zero, whereas O2 evolution continues over ~10 h with gradual bleaching of the colored complexes. This phenomenon is observed neither in the Ag(I)-free PEC reactions nor in the photocatalytic (i.e., bias-free) reactions with Ag(I). This study finds that the role of Ag(I) is not limited as an electron scavenger and calls for more thorough studies on the effect of Ag(I).
Document Type
Article
Published version
Language
English
Subject (CDU)
54 - Chemistry. Crystallography. Mineralogy
Keywords
Electrocatàlisi
Fotocatàlisi
Catalytic mechanisms
Electrocatalysis
Photocatalysis
Pages
9 p.
Publisher
Nature Research
Is part of
Nature Communications. Vol. 11, n.1 (2020), 967
This item appears in the following Collection(s)
Rights
© L'autor/a
Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by/4.0/