Modification of the surface characteristics of anodic alumina membranes using sol–gel precursor chemistry

2003 ◽  
Vol 226 (1-2) ◽  
pp. 75-84 ◽  
Author(s):  
B Winkler
Keyword(s):  
Sol Gel ◽  
Surface Characteristics ◽  
Precursor Chemistry ◽  
Anodic Alumina ◽  
Alumina Membranes ◽  
Modification Of The Surface

Fabrication, characterization, and photoluminescence properties of highly ordered TiO2 nanowire arrays

2001 ◽  
Vol 16 (4) ◽  
pp. 1138-1144 ◽  
Author(s):  
Y. Lei ◽  
L. D. Zhang
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Broad Band ◽  
Anodic Alumina ◽  
Nanowire Arrays ◽  
Photoluminescence Properties ◽  
Alumina Membrane ◽  
Tio2 Nanowire ◽  
Alumina Membranes ◽  
Center Area

Highly ordered TiO2 nanowire arrays were prepared in anodic alumina membranes by a sol-gel method. The nanowires are single-crystalline anatase phase with uniform diameters around 50 nm. At room temperature, photoluminescence (PL) measurements of these TiO2 nanowire arrays showed a visible broad band with three peaks, which were located at about 425, 460, and 530 nm that are attributed to self-trapped excitons, F, and F+ centers, respectively. A model is also presented to explain the PL intensity drop-down of the TiO2 nanowire arrays embedded in the alumina membrane: the blue PL band of the anodic alumina membranes arises from the F+ centers on the pore walls, and the TiO2 nanowires first form in the center area of the pores and then extend to the pore walls.

Preparation of thin anodic alumina membranes and their utilization for template electrodeposition

2016 ◽  
Vol 10 (3) ◽  
pp. 548-553 ◽  
Author(s):  
A. P. Leontiev ◽  
I. V. Roslyakov ◽  
A. S. Vedeneev ◽  
K. S. Napolskii
Keyword(s):  
Anodic Alumina ◽  
Alumina Membranes

NANOSTRUCTURED SnO2/C COMPOSITE ANODES IN LITHIUM-ION BATTERIES

2003 ◽  
Vol 02 (04n05) ◽  
pp. 299-306 ◽  
Author(s):  
CHIEN-TE HSIEH ◽  
JIN-MING CHEN ◽  
HSIU-WEN HUANG
Keyword(s):  
Lithium Ion Batteries ◽  
Discharge Capacity ◽  
Coulombic Efficiency ◽  
Sol Gel ◽  
Lithium Ion ◽  
Surface Characteristics ◽  
Carbon Surface ◽  
Cyclic Voltammograms ◽  
Composite Anodes ◽  
Sol Gel Synthesis

Nanostructured SnO 2/ C composites used as anode materials were prepared by sol–gel synthesis to explore electrochemical properties in lithium-ion batteries. Surface characteristics of the SnO 2/ C nanocomposite were analyzed by X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that nanocrystalline SnO 2/ C with a grain size of 20–50 nm was uniformly dispersed on the carbon surface. After nanocrytalline SnO 2 coated onto carbon, the discharge capacity showed an increase up to 23%, i.e., from 300 to 370 mAh/g at a current density of 0.6 mA/cm2. The nanocomposite anode can achieve a fairly stable discharge capacity and excellent Coulombic efficiency (>99.5%) over 50 cycles. Cyclic voltammograms indicated that the improvements on capacity and cycleability were due to reversible alloying of nanosized Sn and Li on carbon surface.

scholarly journals Anodic Alumina Membranes: From Electrochemical Growth to Use as Template for Fabrication of Nanostructured Electrodes

2022 ◽  
Vol 12 (2) ◽  
pp. 869
Author(s):  
Bernardo Patella ◽  
Salvatore Piazza ◽  
Carmelo Sunseri ◽  
Rosalinda Inguanta
Keyword(s):  
Morphological Characteristics ◽  
Bath Temperature ◽  
Anodic Alumina ◽  
Great Success ◽  
Porous Layers ◽  
Electrochemical Growth ◽  
Alumina Membranes ◽  
Aluminum Ions ◽  
Pore Length ◽  
Alloy Nanowires

The great success of anodic alumina membranes is due to their morphological features coupled to both thermal and chemical stability. The electrochemical fabrication allows accurate control of the porous structure: in fact, the membrane morphological characteristics (pore length, pore diameter and cell density) can be controlled by adjusting the anodizing parameters (bath, temperature, voltage and time). This article deals with both the fabrication and use of anodic alumina membranes. In particular, we will show the specific role of the addition of aluminum ions to phosphoric acid-based anodizing solution in modifying the morphology of anodic alumina membranes. Anodic alumina membranes were obtained at −1 °C in aqueous solutions of 0.4 M H3PO4 added with different amounts of Al(OH)3. For sake of completeness, the formation of PAA in pure 0.4 M H3PO4 in otherwise identical conditions was also investigated. We found that the presence of Al(OH)3 in solution highly affects the morphology of the porous layer. In particular, at high Al(OH)3 concentration (close to saturation) more compact porous layers were formed with narrow pores separated by thick oxide. The increase in the electric charge from 20 to 160 C cm−2 also contributes to modifying the morphology of porous oxide. The obtained anodic alumina membranes were used as a template to fabricate a regular array of PdCo alloy nanowires that is a valid alternative to Pt for hydrogen evolution reaction. The PdCo alloy was obtained by electrodeposition and we found that the composition of the nanowires depends on the concentration of two metals in the deposition solution.

THE EFFECT OF ALUMINUM ELECTROPOLISHING ON NANO-PORES ARRANGEMENT IN ANODIC ALUMINA MEMBRANES

2008 ◽  
Vol 22 (18n19) ◽  
pp. 3267-3277 ◽  
Author(s):  
M. H. RAHIMI ◽  
S. H. TABAIAN ◽  
S. P. HOVEYDA MARASHI ◽  
M. AMIRI ◽  
M. M. DALALY ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Pure Aluminum ◽  
Optical Microscope ◽  
Anodic Alumina ◽  
The Other ◽  
Sem Images ◽  
Current Time ◽  
Nanoporous Anodic Alumina ◽  
Alumina Membranes ◽  
Stress Relieving

Surface conditions of aluminum can influence the final arrangement of nano-pores in fabrication of ordered nanoporous anodic alumina membranes (AAMs). This study is mainly focused on the different applied voltages of aluminum electropolishing by keeping all the other parameters constant. After heat treatment (stress relieving and annealing at 500°C) of pure aluminum sheets, the samples were electropolished at different voltages (10-60V) to obtain desirable surface smoothness, while the temperature of the container was kept constant. The current-time curves were recorded during electropolishing process. The surface roughness obtained in each applied voltage was examined using optical microscope and atomic force microscope (AFM). The process was followed by two-step anodization in order to reach ordered nano-pores. Finally, the influence of surface roughness on regularity of nano-pores was observed using scanning electron microscope (SEM). The SEM images were analyzed to investigate the morphology and the degree of self ordering of pores of the samples by using a new designed analytical method aiming MATLAB and fast Fourier transform (FFT) technique. It was concluded that the electropolishing voltage and the resulted surface roughness and also formed defects can competitively affect the arrangement of membrane's nano-pores. A desired smoothness obtained from electropolishing voltage of 30V. Also 40V provided the best order with respect to the other voltages.

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