Influences of structure and composition on the photoelectrochemical behaviour of anodic films on Zr and Zr–20at.%Ti

Santamaria, Monica; Quarto, F. Di; Habazaki, H.

doi:10.1016/j.electacta.2007.09.046

Cited by 34 publications

(41 citation statements)

References 61 publications

(105 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The best linear regression was observed with the values of n<1. The disclosed supralinear behavior ( 1 n >1) in the investigated potential range confirms the presence of surface and bulk recombination phenomena involving the photogenerated carriers as well as the geminate recombination effects generally occurring in the amorphous film [33]. Geminate recombination phenomenon is typical for materials containing a non-zero density of localized states near Fermi level.…”

Section: Photoelectrochemical Performance Of Electrode Smentioning

confidence: 55%

Photoelectrochemical properties of MoO2 thin films

Dukštienė

Sinkevičiūtė

2013

J Solid State Electrochem

View full text Add to dashboard Cite

Thin MoO 2 films were electrodeposited on a selenium pre-deposited SnO 2 |glass plate. The photoelectrochemical properties of MoO 2 films were investigated in 0.1 M Na 2 SO 4 solution by the ultraviolet-visible spectrophotometry, linear sweep voltammetry, and altering current impedance measurement techniques. It was found that under illumination with the incident light of λ=366 nm, the photo response of the MoO 2 |SnO 2 |glass electrode resulted from the MoO 2 layer, while the SnO 2 layer served as a sink for photogenerated charge carriers. The MoO 2 film exhibited ntype conductivity. A schematic band structure diagram of MoO 2 in 0.1 M Na 2 SO 4 solution was constructed. The flat band potential (E fb ), the donor concentration (N D ), the photogeneration current efficiency depended on MoO 2 film thickness. The [Fe(CN) 6 ] 4−/3− redox PEC cell with MoO 2 | SnO 2 |glass plate as a photoanode was constructed. Power output characteristics such as the open circuit voltage (V OC ), short circuit current (I SC ), the fill factor (FF), and the lightto-electrical conversion efficiency (η) were determined. The maximum light-to-electrical conversion efficiency exhibited by the PEC cell was 0.94 %.

show abstract

Section: Photoelectrochemical Performance Of Electrode Smentioning

confidence: 55%

Photoelectrochemical properties of MoO2 thin films

Dukštienė

Sinkevičiūtė

2013

J Solid State Electrochem

View full text Add to dashboard Cite

show abstract

“…4, therefore A = 1.35 or A = 2.17 for regular d,d metals and s,p-s,p metals mixed oxides, respectively. In previous papers, [30][31][32] we have shown that conditions such as those mentioned above in the paper of Zunger et al can be encountered in practice in the case of passive films grown on valve-metals alloys where, in suitable electrolytic solutions, the oxide composition maintains the same cation ratio present in the metallic alloy. This is reported in Figures 1-3 for d,d-metals mixed oxides, where the measured optical band gaps as a function of the alloys composition are reported for passive films grown on Ti-Zr and Ta-Nb alloys as well as for physically deposited (Gd x Y (1-x) ) 2 O 3 .…”

Section: Theoretical Backgroundmentioning

confidence: 99%

“…This is reported in Figures 1-3 for d,d-metals mixed oxides, where the measured optical band gaps as a function of the alloys composition are reported for passive films grown on Ti-Zr and Ta-Nb alloys as well as for physically deposited (Gd x Y (1-x) ) 2 O 3 . [30][31][32][33][34] The amorphous nature of the passive film on Nb-Ta alloys and the absence of any indirectto-direct optical transition crossover in the case of crystalline films grown on Ti-Zr alloys, allowed testing of the suggestion of Zunger and coworkers 25,26 for the regular semiconducting alloys reported above. Figures 1 and 2 show the dependence of experimental E g values of thin anodic passive films vs alloys composition for Ti-Zr and Ta-Nb mixed oxides.…”

Section: Theoretical Backgroundmentioning

confidence: 99%

Critical Review—Photocurrent Spectroscopy in Corrosion and Passivity Studies: A Critical Assessment of the Use of Band Gap Value to Estimate the Oxide Film Composition

Quarto

Zaffora

Franco

et al. 2017

J. Electrochem. Soc.

View full text Add to dashboard Cite

A critical assessment of the Photocurrent Spectroscopy (PCS) Technique for the semi-quantitative characterization of passive film and corrosion layers composition is carried out. We take into account more than three decades of PCS usage as "in-situ" analytical technique and related results as well as the criticism of the underlying semi-empirical correlation relating the measured optical bandgap (E g ) to the passive film composition. The discrepancies between the experimental data, gathered by PCS measurements, and E g estimates originating from recently developed Density Functional Theory based modeling of solid state properties are stressed with particular emphasis on the case of anodic passive film grown on technologically important alloys (Fe-Cr and stainless steels). The extension of this correlation to mixed oxides and its use for relating the oxide composition to the bandgap values is critically reviewed by comparing the predicted E g of mixed oxides with the experimental values. Suggestions on how to account for different bandgap values of oxide polymorphs and how to correlate the E g values to the composition of mixed s,p-d-metal oxides are presented and discussed on the basis of experimental results reported in the literature. On the basis of this assessment, the ability of PCS in providing quantitative information on the composition of passive film and corrosion layer is generally confirmed. Fujimoto (fujimoto@mat.eng.osaka-u.ac.jp) and HeeJin Jang (heejin@chosun.ac.kr). . This paper is a Critical Review in Electrochemical and Solid State Science and Technology (CRES 3 T). This article was reviewed by ShinjiPhotocurrent Spectroscopy (PCS) is currently employed for the characterization of solid-state properties of semiconducting and insulating materials, since the knowledge of their bandgap is a prerequisite to any possible application in different fields such as solar energy conversion (photoelectrochemical and photovoltaic solar cells, photocatalysis) and microelectronics (high-k, high band-gap materials). 1,2In the last 20-30 years an increasing number of electrochemists working in the field of corrosion have been attracted by this technique owing to its versatility and ability to scrutinize "in-situ" corrosion layers and passive films having semiconducting or insulating behavior. In previous as well as in very recent works 3-7 we have shown that PCS is able to provide detailed information on characteristic energy levels of passive film/electrolyte junctions (flatband potential: U FB ; internal photoemission threshold: E th ; bandgap value: E g ). Such information is necessary for a deeper understanding of the possible mechanisms of charge transfer (electrons and ions) at the metal/corrosion layer/electrolyte interface. Further advantages stem from the fact that the PCS technique does not require particular surface finishing control, it can be used both on large areas as well as in microscopic regions of the electrode, and can reach high sensitivity by using a lock-in amplifier coupled to a mec...

show abstract

“…Further evidence in favour of the proposed corre-lation for anodic films grown on Mo-Ta, Ti-Zr, Hf-W metallic alloys can be found in Refs. [144,[146][147][148]. We have to mention that apart the nature of the oxide other experimental parameters can affect the lattice disorder degree of passive films and then the ΔE am value in anodic films.…”

Section: (Iii) Amorphous Oxide Filmsmentioning

confidence: 99%

“…We have to mention that apart the nature of the oxide other experimental parameters can affect the lattice disorder degree of passive films and then the ΔE am value in anodic films. 127,143,146 …”

Section: (Iii) Amorphous Oxide Filmsmentioning

confidence: 99%