Highly ordered anodic hafnium oxide (AHO) nanoporous or nanotubes were synthesized by electrochemical anodization of Hf foils. The growth of self-ordered AHO was investigated by optimizing a key electrochemical anodization parameter, the solvent-based electrolyte using: Ethylene glycol, dimethyl sulfoxide, formamide and N-methylformamide organic solvents. The electrolyte solvent is here shown to highly affect the morphological properties of the AHO, namely the self-ordering, growth rate and length. As a result, AHO nanoporous and nanotubes arrays were obtained, as well as other different shapes and morphologies, such as nanoneedles, nanoflakes and nanowires-agglomerations. The intrinsic chemical-physical properties of the electrolyte solvents (solvent type, dielectric constant and viscosity) are at the base of the properties that mainly affect the AHO morphology shape, growth rate, final thickness and porosity, for the same anodization voltage and time. We found that the interplay between the dielectric and viscosity constants of the solvent electrolyte is able to tailor the anodic oxide growth from continuous-to-nanoporous-to-nanotubes.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7075290 | PMC |
http://dx.doi.org/10.3390/nano10020382 | DOI Listing |
Materials (Basel)
November 2024
NANOTECH Centre, Ural Federal University, Mira Str., 19, 620002 Ekaterinburg, Russia.
Nanotubular hafnia arrays hold significant promise for advanced opto- and nanoelectronic applications. However, the known studies concern mostly the luminescent properties of doped HfO-based nanostructures, while the optical properties of nominally pure hafnia with optically active centers of intrinsic origin are far from being sufficiently investigated. In this work, for the first time we have conducted research on the wide-range temperature effects in the photoluminescence processes of anion-defective hafnia nanotubes with an amorphous and monoclinic structure, synthesized by the electrochemical oxidation method.
View Article and Find Full Text PDFSmall
November 2024
School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, People's Republic of China.
The preparation of ethylene from ethane, a main component of shale gas, has become an important process of the petrochemical industry, using ethane steam cracking at high temperatures (>900 °C), which is a highly energy intensive industry. Here, direct dehydrogenation of ethane is engineered electrochemically to produce ethylene and hydrogen in a proton-conducting electrolysis cell, achieving over 50% ethane conversion and 90.42% ethylene selectivity at 700 °C.
View Article and Find Full Text PDFNanoscale
August 2024
Institute of Electronics, National Yang-Ming Chiao Tung University, Hsinchu 30010, Taiwan, Republic of China.
Transparent memristor-based neuromorphic synapses are expected to be specialised devices for high-speed information transmission and processing. The synaptic linearity and potentiation/depression cycles are imperative issues for the application of memristors. This work explores a memristor for improving switching uniformity by introducing a thin HfO interfacial layer as a diffusion-limiting layer sandwiched between WO and ITO bottom electrodes.
View Article and Find Full Text PDFSci Rep
July 2024
Department of Physics, School of Natural Sciences, Shiv Nadar Institution of Eminence (SNIoE), Deemed to be University, Delhi-NCR, Greater Noida, 201314, India.
Pioneering flexible micro-supercapacitors, designed for exceptional energy and power density, transcend conventional storage limitations. Interdigitated electrodes (IDEs) based on laser-induced graphene (LIG), augmented with metal-oxide modifiers, harness synergies with layered graphene to achieve superior capacitance. This study presents a novel one-step process for sputtered plasma deposition of HfO, resulting in enhanced supercapacitance performance.
View Article and Find Full Text PDFACS Nano
July 2024
Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!