Photo-electrochemical activity and selectivity of nanocrystalline BaTiO3 electrodes in water oxidation

0533063 - ÚFCH JH 2022 RIV DE eng J - Journal Article
Klusáčková, Monika - Nebel, Roman - Krtil, Petr - Krýsová, Hana - Pittkowski, Rebecca - Minhová Macounová, Kateřina
Photo-electrochemical activity and selectivity of nanocrystalline BaTiO3 electrodes in water oxidation.
Electrochemical Science Advances. Roč. 1, č. 2 (2021), č. článku e2000005. ISSN 2698-5977
R&D Projects: GA ČR(CZ) GA17-12800S; GA MŠMT(CZ) LM2018124; GA MŠMT(CZ) EF16_013/0001821
EU Projects: European Commission(XE) 722614 - ELCOREL
Grant - others:GA MŠk(CZ) CZ.02.1.01/0.0/0.0/16_013/0001821; Akademie věd - GA AV ČR(CZ) L200402001
Institutional support: RVO:61388955
Keywords : barium titanate * photo-electrochemistry * water oxidation
OECD category: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)
Method of publishing: Open access

Nanocrystalline BaTiO3 photocatalysts were prepared by spray-freeze/freezedrying
procedure in presence of structure directing gelatin. The synthetic
approach yields materials with particle sizes ranging between 20 and 60 nm
conforming to cubic perovskite structure. Regardless of the structural differences,
the materials show particle size independent bandgap energy of ca.
3.27 eV. All prepared materials are photo-electrochemically active in water oxidation
with intrinsic activity decreasing with decreasing particle size. The photoelectrochemical
activity of BaTiO3 in water oxidation is pH dependent with the
hole charge transfer processes being significantly suppressed in alkaline media.
Such a behavior can be ascribed to deprotonation of surface OH groups encountered
in alkaline media that promotes surface state catalyzed electron transfer
reactions at the illuminated BaTiO3 surface. The barium titanate shows the ability
to oxidize water with formation of oxygen and ozone. The ozone formation is
pronounced on large nanocrystals particularly in acid media. No ozone formation
was observed in alkaline solutions.
Permanent Link: http://hdl.handle.net/11104/0311558