Tailoring the protonic conductivity of porous yttria-stabilized zirconia thin films by surface modification
| Autor: | Rajendra S. Negi, Andrey Mazilkin, Torsten Brezesinski, Matthias T. Elm, Erdogan Celik, Michele Bastianello, Dominic Boll |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Technology
Materials science General Physics and Astronomy 02 engineering and technology Conductivity 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Amorphous solid Pulsed laser deposition 2020-023-028491 Atomic layer deposition FIB Chemical engineering Proton transport TEM Surface layer Physical and Theoretical Chemistry Thin film 0210 nano-technology ddc:600 Yttria-stabilized zirconia |
| Zdroj: | Physical chemistry, chemical physics, 22 (20), 11519–11528 |
| ISSN: | 1463-9076 1463-9084 |
| Popis: | Porous yttria-stabilized zirconia (YSZ) thin films were prepared by pulsed laser deposition to investigate the influence of specific surface area on the electronic, oxygen ion, and protonic transport properties. Electrochemical impedance spectroscopy was carried out as a function of temperature, oxygen activity and humidity of the surrounding atmosphere. At high humidity, protons on the surface of the porous YSZ thin films lead to increased conductivity, even for temperatures up to 700 °C. With increasing relative humidity, the activation energy of proton transport decreases because of changes in the transport mechanism from Grotthuss-type to vehicle-type transport. By coating the porous YSZ films with an amorphous titania (TiO2) layer of only a few nanometer thickness using atomic layer deposition, the protonic contribution to conductivity is significantly reduced. Depositing an 18 nm-thick anatase TiO2 surface layer, the protonic conductivity contribution increases again, which can be attributed to enhanced capillary condensation because of the lower pore size. Interestingly, the filling of pores is accompanied by a decrease in proton mobility. Theses results demonstrate the significant effect that the porosity and the surface properties have on the protonic transport and further provide new design principles for developing nanostructured proton-conducting oxides. |
| Databáze: | OpenAIRE |
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