Plasma-sprayed semiconductor electrodes: photoelectrochemical properties of TiO₂

From National Research Council Canada

DOI	Resolve DOI: https://doi.org/10.1149/1.2113629
Author	Search for: Parent, L.; Search for: Dodelet, J. P.; Search for: Ross, G. G.; Search for: Terreault, B.; Search for: Dallaire, S.¹
Affiliation	National Research Council of Canada
Format	Text, Article
Subject	TiO₂; semiconductor; photoanode; plasma spray technique; photoelectrochemistry
Abstract	TiO₂ photoanodes have been prepared by the plasma spray technique on titanium, graphite, and alumina substrates. 25–30 μm thickcoatings display a good adhesion to the substrate and a highly textured surface. Dark and photoelectrochemical propertiesof the photoanodes have been measured in oxygen‐saturated solutions of NaOH at pH 13. It is shown that the performances of the electrodes are quite insensitive to the plasma power or to the TiO₂ powder granulation but are very sensitive to the purity of the spraying material, to the substrate, and also to a heat‐treatment(H₂ or Ar at 800°C followed by a rapid quenching in air). The maximum quantum yield is obtained at 300 nm for heat‐treated TiO₂ . It is about 40% on alumina and 70% on the titanium. The heat‐treatment affects the conductivity, σ, and the surface densityof hydroxyl groups, Noh , of the coatings. For heat‐treated TiO₂ , typical values are σ = 2.4(Ω cm)⁻¹ and Noh = 2.8 x 10¹⁶ cm⁻² . For untreated TiO₂ , typical values are σ = 30.6(Ωcm)⁻¹ and Noh + 2.1 X 10¹⁶ cm ⁻². The J‐V curves of heat‐treated TiO₂ sprayed on alumina extend anodically up to 9.5V (vs. SCE), where film breakdown occurs. For the same film sprayed on titanium and graphite, the anodic dark behavior is similarto that observed for the bare substrates. It is concluded that polycrystalline TiO₂ coatings, produced by the plasma spray technique, can display photoelectrochemical and dark characteristics similar to theones obtained with single‐crystal material.
Publication date	1985-12-31
Publisher	Electrochemical Society
In	Journal of The Electrochemical Society 132, no. 11: 2590–2593.
Language	English
Peer reviewed	Yes
NRC number	CNRC 26219 NRC-IGM85-301-166
Export citation	Export as RIS
Report a correction	Report a correction (opens in a new tab)
Record identifier	6acdc306-7b56-4cc5-90c1-dc754bfa1d3e
Record created	2019-03-26
Record modified	2020-03-17

Date modified:: 2024-07-21