Templated fabrication of nanostructured Ni brush for hydrogen evolution reaction

2010 ◽  
Vol 25 (10) ◽  
pp. 2001-2007 ◽  
Author(s):  
Sheng-Chieh Lin ◽  
Yu-Fan Chiu ◽  
Pu-Wei Wu ◽  
Yi-Fan Hsieh ◽  
Cheng-Yeou Wu
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Anodic Aluminum Oxide ◽  
Electroless Deposition ◽  
Pore Diameter ◽  
Pore Channel ◽  
Average Pore ◽  
Anodic Aluminum ◽  
Anodization Process ◽  
Pore Opening

We fabricated a nanostructured brush by carrying out Ni deposition on a through-channel anodic aluminum oxide (AAO) template, followed by removal of the AAO skeleton. The AAO was prepared by a two-step anodization process resulting in pore diameter and thickness of 350 nm and 40 μm, respectively. Subsequently, the AAO underwent an electroless deposition involving sensitization, activation, and Ni plating, in conjunction with polyethylene glycol used as the inhibitor to prevent premature closing of pore opening. After deliberate control in relevant parameters, we obtained a conformal Ni overcoat along every pore channel leading to a reduced average pore diameter of 78 nm. Afterward, the sample was immersed in a KOH solution to remove the AAO structure, forming freestanding Ni tubules in a brush configuration. The nanostructured brush revealed considerable enhancement for hydrogen evolution reaction in both current-potential polarization and galvanostatic measurements, which were attributed to the increment in apparent surface area.

Fabrication of Low Cost Membrane from Anodic Aluminum Oxide

2017 ◽  
Vol 751 ◽  
pp. 363-367
Author(s):  
Peerawith Sumtong ◽  
Apiluck Eiad-Ua
Keyword(s):  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Pore Diameter ◽  
Average Pore Diameter ◽  
Process Conditions ◽  
Low Grade ◽  
Pore Density ◽  
Average Pore ◽  
Anodic Aluminum ◽  
Interpore Distance

Anodic Aluminum Oxide (AAO) membrane has been successfully fabricated from two-step anodization with aluminum low grade (Al6061). The pore density, the pore diameter, and the interpore distance can be controlled by varying anodization process conditions. However, there are limits to control the mechanical strength and growth of AAO arrays, such as pore density, pore diameter and interpore distance. In this research the self-organized two-step anodization is carried out varying time at 24, 48 and 72 hours, respectively with 40V at the low temperature 2-5°C. The optimum conditions of AAO with two-step anodization is 40V for 48 hr. Finally, AAO substrate is separated from aluminum low-grade and enlarged pore diameter with pore widening process by 5% H3PO4. The physical properties were investigated by mean of field emission scanning electron microscope (FE-SEM) show that the average pore diameter and average interpore distance increase with the anodization time. Al6061 Aluminum substrate can be used to fabricate a nanoporous AAO film with an average pore diameter and average interpore distance larger than 70 and 90 nanometers, respectively but less mechanical stability.

Nanoporous Anodic Aluminum Oxide (AAO) Thin Film Fabrication with Low-Grade Aluminium

2016 ◽  
Vol 872 ◽  
pp. 152-156
Author(s):  
Peerawith Sumtong ◽  
Apiluck Eiad-Ua ◽  
Khattiya Chalapat
Keyword(s):  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Pore Diameter ◽  
Average Pore Diameter ◽  
Process Conditions ◽  
Low Grade ◽  
Average Pore ◽  
Aluminium Substrate ◽  
Anodization Time ◽  
Anodic Aluminum

Anodic aluminum oxide (AAO) is well known for its nanoscopic structures and its applications in microfluidics, sensors and nanoelectronics. The pore density, the pore diameter, and the interpore distance of an AAO substrate can be controlled by varying anodization process conditions. In this research, the self-organized two-step anodization is carried out with a low-grade (Al6061) aluminium substrate using a 40V voltage at the temperature of 2 to 5 °C. Three experiments are done with the anodization time of 24 hours, 48 hours and 72 hours. The structural features of AAO are characterized by a field emission electron microscope (FE-SEM). The data from FE-SEM show that the average pore diameter increases with the anodization time, and that the Al6061 aluminium substrate can be used to fabricate a nanoporous AAO film with an average pore diameter smaller than 17 nanometers.

scholarly journals Challenges to Fabricate Large Size-Controllable Submicron-Structured Anodic-Aluminum-Oxide Film

2017 ◽  
Vol 2 (2) ◽  
pp. 65-72 ◽  
Author(s):  
Jin Shyong Lin ◽  
Shih Hsun Chen ◽  
Ker Jer Huang ◽  
Chien Wan Hun ◽  
Chien Chon Chen
Keyword(s):  
Aluminum Oxide ◽  
Anodic Aluminum Oxide ◽  
Local Heat ◽  
Large Sample Size ◽  
Average Pore ◽  
Anodic Aluminum Oxide Film ◽  
Anodic Aluminum ◽  
Aluminum Sheets ◽  
Large Size ◽  
Anodization Process

Anodic aluminum oxide (AAO) is well known for its unique controllable structure and functional contributions in research and developments. However, before AAO can be widely used in the industry, some engineering problems should be overcome. In this study, we designed a novel electrochemical mold, which can resolve the exothermal problem for large-size aluminum sheets during high-voltage anodization process. AAO film with a large sample size of 11 x 11 cm2 in area, 148 μm in thickness and 450 nm in average pore diameter, decorated with ordered-pattern structure, was successfully obtained through a 200 V anodization process. It was noticed that the local heat was generated with increasing the anodizing voltage, resulting in undesired pits and burr defects on the AAO surface. In order to retain AAO’s quality and reduce the producing cost of the anodization process, a mass producing system combining with an overhead conveyor was proposed. The convenient anodization system, novel electrochemical mold and bath may help to fabricate high-quality AAO films efficiently.

scholarly journals Influence of the anodization conditions and chemical treatment on the formation of alumina membranes with defined pore diameters

2021 ◽  
Author(s):  
Iwona Dobosz
Keyword(s):  
Aluminum Oxide ◽  
Chemical Treatment ◽  
Anodic Aluminum Oxide ◽  
Pore Diameter ◽  
Operating Conditions ◽  
Oxide Growth ◽  
Pore Density ◽  
Anodic Aluminum ◽  
Pore Widening ◽  
Oxide Membranes

AbstractPorous anodic aluminum oxide membranes were fabricated via two-step anodization of aluminum in 0.3 M H2C2O4, 0.3 M H2SO4 and 0.17 M H3PO4 solutions. The parameters of the oxide film such as: pore diameter (Dp), interpore distance (Dc), porosity (P) and pore density (ρ) can be completely controlled by the operating conditions of the anodization. Additionally, the pore diameters and pore density can be controlled via a chemical treatment (pore opening/widening process). The effect of anodizing conditions such as the applied voltage, type of electrolyte and purity of the substrate on the rate of porous oxide growth are discussed. The obtained results were compared with the theoretical predictions and data that has been reported in the literature. The influence of the duration of chemical etching on the structural features of the oxide membranes was studied. On the based on qualitative and quantitative FFT analyzes and circularity maps, it was found that the nanostructures of anodized aluminum have the maximum order under certain specified conditions. The presence of alloying elements affects not only the rate of oxide growth but also the morphology of the anodic aluminum oxide. The rate of oxide growth depends on the electrolyte type and temperature. During chemical treatment of the oxide films pore diameter increases with the pore widening time and the highest pore widening was observed in phosphoric acid solution.

Electroless deposition of Ni–Cu–P on a self-supporting graphene with enhanced hydrogen evolution reaction activity

2020 ◽  
Vol 45 (27) ◽  
pp. 13985-13993 ◽  
Author(s):  
Xiangyu Liu ◽  
Jianbing Zang ◽  
Shuyu Zhou ◽  
Pengfei Tian ◽  
Hongwei Gao ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Electroless Deposition

Fabrication of Low Cost Anodic Aluminum Oxide (AAO) Tubular Membrane and their Application for Hemodialysis

2012 ◽  
Vol 550-553 ◽  
pp. 2040-2045 ◽  
Author(s):  
Ajab Khan Kasi ◽  
Jafar Khan Kasi ◽  
Mahadi Hasan ◽  
Nitin Afzulpurkar ◽  
Sirapat Pratontep ◽  
...  
Keyword(s):  
Anodic Aluminum Oxide ◽  
Pore Diameter ◽  
Low Cost ◽  
Membrane Thickness ◽  
Low Grade ◽  
Fluid Filtration ◽  
Tubular Membrane ◽  
Anodic Aluminum ◽  
Self Organized ◽  
Impurity Defects

This paper reports the fabrication of AAO tubular membrane using 99.35% and 99.56% pure Al and their potential application for hemodialysis. Here we discussed the effect of impurity on membrane structure. We found that the self organized structure of AAO nanochannels minimizes impurity defects in membrane. If micro size impurity blocks the generation of nanochannels then the neighboring nanochannels bend and make branches to fulfill that gap. We observed that if impurity size is less than the AAO membrane thickness then it does not produce any micro size hole. In low grade Al the periodic hexagonal order was disturbed however there was no big difference in pore diameter. It was observed that such type of membrane do not have any leakage and it can be used for fluid filtration. The fabricated tubular membrane was used for hemodialysis successfully. The hemodialysis results show that AAO tubular membrane can be used for both diffusive and convective filtration

Rhenium electroless deposition on p-Si(100) from HF solutions under illumination: Hydrogen evolution reaction onto p-Si/Re systems

2009 ◽  
Vol 633 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Eduardo C. Muñoz ◽  
Ricardo S. Schrebler ◽  
Paula C. Grez ◽  
Rodrigo G. Henríquez ◽  
Cristopher A. Heyser ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Electroless Deposition

Electroless deposition of Au/Pt/Pd nanoparticles on p-Si(111) for the light-induced hydrogen evolution reaction

2015 ◽  
Vol 244 ◽  
pp. 3-9 ◽  
Author(s):  
M. Metzler ◽  
A. Thorwart ◽  
S. Zeller ◽  
T. Diemant ◽  
R.J. Behm ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Electroless Deposition ◽  
Pd Nanoparticles
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