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Detailed Comparative Analysis of Structural Stability and Electron-Phonon Properties of ZrO2: Mechanism of Water Adsorption on t-ZrO2 (101) and t-YSZ (101) Surfaces
Version 1
: Received: 17 July 2023 / Approved: 18 July 2023 / Online: 18 July 2023 (07:06:38 CEST)
Version 2
: Received: 19 July 2023 / Approved: 19 July 2023 / Online: 20 July 2023 (02:32:18 CEST)
Version 3
: Received: 20 July 2023 / Approved: 20 July 2023 / Online: 21 July 2023 (02:30:00 CEST)
Version 4
: Received: 27 July 2023 / Approved: 28 July 2023 / Online: 28 July 2023 (09:39:55 CEST)
Version 5
: Received: 19 September 2023 / Approved: 20 September 2023 / Online: 20 September 2023 (08:34:44 CEST)
Nematov, D.D.; Burhonzoda, A.S.; Kholmurodov, K.T.; Lyubchyk, A.I.; Lyubchyk, S.I. A Detailed Comparative Analysis of the Structural Stability and Electron-Phonon Properties of ZrO2: Mechanisms of Water Adsorption on t-ZrO2 (101) and t-YSZ (101) Surfaces. Nanomaterials2023, 13, 2657.
Nematov, D.D.; Burhonzoda, A.S.; Kholmurodov, K.T.; Lyubchyk, A.I.; Lyubchyk, S.I. A Detailed Comparative Analysis of the Structural Stability and Electron-Phonon Properties of ZrO2: Mechanisms of Water Adsorption on t-ZrO2 (101) and t-YSZ (101) Surfaces. Nanomaterials 2023, 13, 2657.
Nematov, D.D.; Burhonzoda, A.S.; Kholmurodov, K.T.; Lyubchyk, A.I.; Lyubchyk, S.I. A Detailed Comparative Analysis of the Structural Stability and Electron-Phonon Properties of ZrO2: Mechanisms of Water Adsorption on t-ZrO2 (101) and t-YSZ (101) Surfaces. Nanomaterials2023, 13, 2657.
Nematov, D.D.; Burhonzoda, A.S.; Kholmurodov, K.T.; Lyubchyk, A.I.; Lyubchyk, S.I. A Detailed Comparative Analysis of the Structural Stability and Electron-Phonon Properties of ZrO2: Mechanisms of Water Adsorption on t-ZrO2 (101) and t-YSZ (101) Surfaces. Nanomaterials 2023, 13, 2657.
Abstract
The paper considers the issues of structural stability, electronic properties, and phonon dispersion of the cubic, tetragonal, and monoclinic phases of ZrO2. It was found that the monoclinic phase of zirconium dioxide is the most stable among the other two phases in terms of total energy, lowest enthalpy, highest entropy, and other thermodynamic values. The smallest negative modes were found for m-ZrO2. An analysis of the electronic properties showed that during the m–t phase transformation of ZrO2, the Fermi level first shifts by 0.125 eV towards higher energies, and then decreases by 0.08 eV in the t–c cross section. The band gap for c-ZrO2, t-ZrO2, and m-ZrO2 is 5.140 eV, 5.898 eV, and 5.288 eV, respectively. Calculations based on the analysis of the influence of doping 3.23, 6.67, 10.35 and 16.15 mol. %Y2O3 on the m-ZrO2 structure showed that the enthalpy of m-YSZ decreases linearly, which accompanies further stabilization of monoclinic ZrO2 and an increase in their defectiveness. In this case, the position of the Fermi level changes abruptly, and the energy gap decreases. It has been established that not only for pure systems, including those doped with Y2O3, the main contribution to the formation of the conduction band is made by the p-states of electrons. An analysis of the mechanism of water adsorption on the surface of t-ZrO2 (101) and t-YSZ (101) showed that H2O on unstabilized t-ZrO2 (101) is adsorbed dissociatively with an energy of -1.22 eV, as well as by the method of molecular chemadsorption with an energy of -0.69 eV and the formation of a hydrogen bond with a bond length of 1.01 Å. In the case of t-YSZ (101), water is molecularly adsorbed onto the surface with an energy of -1.84 eV. Dissociative adsorption of water occurs at an energy of -1.23 eV, near the yttrium atom.
Keywords
zirconia; stability; yttrium-stabilized zirconia; phase transition; Fermi level shift; water adsorption on the surface
Subject
Physical Sciences, Condensed Matter Physics
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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Commenter: Dilshod Nematov
Commenter's Conflict of Interests: Author