Oxygen Vacancy: The Invisible Agent on Oxide Surfaces

Pacchioni, Gianfranco

doi:10.1002/cphc.200300835

Cited by 456 publications

(364 citation statements)

References 42 publications

Supporting

Mentioning

352

Contrasting

Unclassified

Order By: Relevance

“…Using isotopically labeled oxygen it has been demonstrated that the oxygen atom incorporated in the organic reactant does not come from the gas phase but directly from the oxide surface [74]. Clearly, the cost of removing an oxygen atom from the surface of the catalyst with formation of an oxygen vacancy is an essential parameter in determining both the kinetics and the thermodynamics of the reaction [75].…”

Section: The Thermochemistry Problemmentioning

confidence: 99%

First Principles Calculations on Oxide-Based Heterogeneous Catalysts and Photocatalysts: Problems and Advances

Pacchioni

2014

Catal Lett

Self Cite

View full text Add to dashboard Cite

Density functional theory (DFT) has become an essential complement of experiments to interpret, rationalize, and understand structures, spectroscopic data, microscopy analyses, etc. of relevance in heterogeneous catalysis and photocatalysis. However, one of the major goals of theory in catalysis remains the prediction of reaction enthalpies and entropies, of transition state structures, and the identification of reaction mechanisms. While accurate theoretical methods are currently available to study the thermochemistry of molecular systems, this is much less so when reactions involve solid surfaces and in particular oxide materials. The problem stems from the approximate nature of the exchange-correlation functionals used in all DFT approaches. Attempts to improve the accuracy of reaction energies is at the core of the efforts made in the past 30 years to generate new functionals. In this review we will discuss some recent advances in the theoretical description of oxides and their surfaces in heterogeneous catalysis and photocatalysis. In particular, we will focus on two problems: (1) the determination of an oxide band gap and the proper alignment of the occupied and unoccupied levels with respect to the vacuum level, an aspect relevant for the red-ox properties of the material, and (2) the calculation of reaction energies at oxide surfaces. To this end, we will discuss and comment on the performance of current implementations of exchange-correlation functionals (standard GGA, GGA?U, hybrid functionals, meta-GGA, etc.) or alternative approaches (like the quasiparticle GW method), in predicting band alignment and chemical reactivity at oxide surfaces. The role of dispersion forces will be also briefly discussed.

show abstract

Section: The Thermochemistry Problemmentioning

confidence: 99%

First Principles Calculations on Oxide-Based Heterogeneous Catalysts and Photocatalysts: Problems and Advances

Pacchioni

2014

Catal Lett

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although transport of charge carriers across the semiconductor surface is a complex process, the electron transport dynamics is satisfactorily described by field effects arising from the coulombic charge of both the charge carriers and surface states (including oxygen states O n-), and iii) electron-lattice interactions [3][4][5][6][7]12,14,29,33]. G* is also a parameter that includes the influence on the surface by the gas-phase surroundings and accounts for the concentration of reactive gas-phase [46].…”

Section: Filmsmentioning

confidence: 99%

“…and iv) segregation of lattice oxygen at high temperatures [1,[3][4][5]. In particular, the formation of oxygen species arising from chemisorption of molecular oxygen promotes significant changes in surface electrochemical potential.…”

Section: Introductionmentioning

confidence: 99%

“…O 2ˉ, Oˉ, O 2-) that exist as a result of both the adsorption of molecular oxygen and electron transfer reactions. Oxygen species promote the operation of electrical fields in the metal-oxide surface, modify charge carrier concentration, cause bending of the conduction level and shifts in the energy of Fermi electrons near the metal-oxide surface [3][4][5][6][7][8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of carrier states in CuWO4 thin-films at elevated temperatures using conductometric analysis

Gonzalez¹,

Dunford²,

Du³

et al. 2013

Journal of Solid State Chemistry

View full text Add to dashboard Cite

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1016/j.jssc.2013.02.002 Chemistry, 201, pp. 35-40, 2013-02-10 Characterization of carrier states in CuWO4 thin-films at elevated temperatures using conductometric analysis Gonzalez, Carlos M.; Dunford, Jeffrey L.; Du, Xiaomei; Post, Michael L. Abstract: CuWO 4 thin-films were deposited by pulsed laser deposition onto an insulating substrate. The temperature dependence of the electronic conductivity of CuWO 4 thin-films was determined over the 100 °C -500 °C temperature range in a synthetic air atmosphere. Additionally, variations of conductivity at 300°C and 500°C have been measured for oxygen partial pressures (0.1 atm < p(O 2 ) < 0.9 atm) in nitrogen. The apparent activation energy ∆E a for the electrical conduction has been estimated. The study of the temperature effect on the electron transport properties of CuWO 4 thin-films reveals the operation of two temperature-dependent oxygen states. The effect of varying oxygen concentration on the electronic properties is discussed in detail. The electrochemical nature of the operating oxygen states for the 100°C -500 °C temperature range is deduced using a physicochemical model that relates electronic conductivity with oxygen partial pressure and temperature. Journal of Solid State Characterization of Carrier States in CuWO

show abstract

“…The surface properties of these materials, in turn, are often highly infl uenced by surface defect structure [1], [2], [3] and [4]. Defects have been shown to be important in TMO electronic, magnetic, and chemical properties and span a wide range of scale, including oxygen vacancies [1], [2], [3], [5], [6], [7] and [8], metal interstitials and adatoms [1] and [9], crystal shear planes [4] and [10], step-defects [4], [10], [11] and [12], meso-to macroscopic scale pits, protrusions, and related large-scale imperfections [13], [14] and [15], the latter of which often have a complicated morphology with a range of atomic-scale defects in their own right [16], [17], [18] and [19]. The surface defect nature may be infl uenced by bulk structure and impurity concentration [1], [4] and [20], introduced by surface preparation methods [12] and [21], or result from chemical reactivity and corrosion properties of the substrate surface [1], [2], [3], [5], [6] and [22].…”

mentioning

confidence: 99%

Novel mesoscale defect structure on NiO(100) surfaces by atomic force microscopy

2006

View full text Add to dashboard Cite

Part of the Chemistry CommonsThis Article is brought to you for free and open access by the Published Research -Department of Chemistry at DigitalCommons@University of Nebraska -Lincoln. It has been accepted for inclusion in Marjorie A. Langell Publications by an authorized administrator of DigitalCommons@University of Nebraska -Lincoln.Petitto, S. C.; Berrie, Cindy L.; and Langell, Marjorie , "Novel mesoscale defect structure on NiO(1 0 0) surfaces by atomic force microscopy" (2006). Marjorie A. Langell Publications. 12.

show abstract

Oxygen Vacancy: The Invisible Agent on Oxide Surfaces

Cited by 456 publications

References 42 publications

First Principles Calculations on Oxide-Based Heterogeneous Catalysts and Photocatalysts: Problems and Advances

First Principles Calculations on Oxide-Based Heterogeneous Catalysts and Photocatalysts: Problems and Advances

Characterization of carrier states in CuWO4 thin-films at elevated temperatures using conductometric analysis

Novel mesoscale defect structure on NiO(100) surfaces by atomic force microscopy

Contact Info

Product

Resources

About