In this work, anodically grown ZrO2 nanotubes (NTs) are examined for the first time for use in micro solid oxide fuel cell (μ-SOFC) applications. This is due to their high surface area to volume ratio and useful nanoscale morphological features (e.g., 5-100 nm thick NT bases that could serve as the electrolyte layer). To understand their full potential for these applications, the determination of their electrical properties is necessary. Therefore, ZrO2 NTs, in the form of a uniform and crack-free film, were obtained by the two-step anodization of Zr foil in aqueous solutions. The films exhibited excellent adhesion to the Zr substrate, which facilitated impedance spectroscopy analyses, used for the first time to obtain the resistivity of the nanotubular array separately from the contact resistances. This gave a conductivity of the ZrO2 NTs of 1.6 × 10(-6) S cm(-1) at 600 °C in N2, approximately twice that reported for dense ZrO2 films measured at the same temperature in air, and also a very reasonable activation energy of 0.90 eV in the 400-600 °C temperature range.
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http://dx.doi.org/10.1039/c5nr00303b | DOI Listing |
RSC Adv
January 2025
Department of Solid State Physics and Nonlinear Physics, Faculty of Physics and Technology, AL-Farabi Kazakh National University Almaty 050040 Kazakhstan.
In this paper, Gd-doped ZrO gate dielectric films and metal-oxide-semiconductor (MOS) capacitors structured as Al/ZrGdO /Si were prepared using an ultraviolet ozone (UVO)-assisted sol-gel method. The effects of heat treatment temperature on the microstructure, chemical bonding state, optical properties, surface morphology and electrical characteristics of the ZrGdO composite films and MOS capacitors were systematically investigated. The crystalline phase of the ZrGdO films appeared only at 600 °C, indicating that Gd doping effectively inhibits the crystallization of ZrO films.
View Article and Find Full Text PDFLangmuir
January 2025
Chemistry and Structure of novel Materials, University of Siegen, Paul-Bonatz Strasse 9-11, 57068 Siegen, Germany.
The surface charge of metal oxides is an important property that significantly contributes to a wide range of phenomena, including adsorption, catalysis, and material science. The surface charge can be predicted by determining the isoelectric point (IEP) of a material and the pH of a solution. Although there have been several studies of the IEP of metal oxide (nano)particles, only a few have reported the IEP of metal oxide films.
View Article and Find Full Text PDFAdv Mater
January 2025
Beijing National Center for Electron Microscopy and Laboratory of Advanced Materials, Department of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China.
HfO/ZrO-based ferroelectrics present tremendous potential for next-generation non-volatile memory due to their high scalability and compatibility with silicon technology. Unlike the continuous polar layers in perovskite ferroelectrics, HfO/ZrO-based ferroelectrics are composed of alternating polar layers with oxygen shifts and non-polar spacers, which leads to a distinct ferroelectric switching mechanism. However, directly observing the switching process has been a big challenge due to the polymorph feature of nanoscale fluorites and the difficulty in in situ imaging on light elements.
View Article and Find Full Text PDFSci Bull (Beijing)
December 2024
Department of Chemistry, Laboratory of Advance Materials, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, State Key Laboratory of Molecular Engineering of Polymers, and iChEM, Fudan University, Shanghai 200433, China. Electronic address:
Hierarchical organization is prevalent in nature, yet the artificial construction of hierarchical materials featuring asymmetric structures remains a big challenge. Herein, we report a stress-induced self-assembly strategy for the synthesis of hierarchically twisted stripe arrays (HTSAs) with mesoporous structures. A soft and thin mesostructured film assembled by micelles and TiO oligomers is the prerequisite.
View Article and Find Full Text PDFDalton Trans
January 2025
Departamento de Química Inorgánica, Facultad de Química y Farmacia, Centro de Energía UC, Centro de Investigación en Nanotecnología y Materiales Avanzados CIEN-UC, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna, 4860, Santiago, Chile.
Recalcitrant pollutants are challenging to degrade during water treatment processes. Methylene blue (MB), a cationic dye, is particularly resistant to degradation and is environmentally persistent. Heterogeneous photocatalysis has emerged as a suitable strategy for removing such pollutants from water.
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