Papers by Keyword: Electrodeposition

Abstract: Cerium oxide (CeO₂) or known as ceria were deposited on titanium dioxide, TiO₂, nanotubes by electrodeposition process as to produce hybrid materials that can generate photocurrent. The electrodeposition process is done by using 0.1 M cerium chloride mixed with 0.1 M ammonium acetate as ligands to promote stability complexes in a standard two electrode bath. Voltage and pH were controlled to ensure the most optimum condition of cerium oxide deposition. Samples were then annealed at different temperatures. Photocurrent results indicate that annealed sample at 450°C shows the best photocurrent due to high degree of anatase and cubic crystallinity.

Abstract: Abstract: Thin anodic alumina (AAO) templates with uniform nanoscale pore diameters and interpore distances were fabricated by a two-step anodization technique on a Si-based (AAO/Ti/Si structure) under controllable anodizing conditions. The obtained thin AAO templates were approximately 60 nm in pore diameter and 1.2 µm in length with 110 nm interpore distances in area of 1 cm². A bottom barrier layer of the anodic alumina (AAO) templates was removed by a wet etching using phosphoric acid (5 wt%) under control of etching time. As an application, Cu nanorods arrays embedded in anodic alumina (AAO) template were fabricated by electrodeposition. The morphologies and structure of the templates and the Cu nanorods produced were analyzed using Field-emission scanning electron microscope (FESEM), Energy dispersive x-ray spectroscopy (EDX) and X-ray diffraction (XRD).

Abstract: In this thesis we provide the electrodeposition technology by means of monolayer templates for fabricating regularly hexagonal array of copper surface, predict the wetting transformation in theory. We report the result that original hydrophilic copper surface may turn to be hydrophobic surface by this kind of structurization. The apparent contact angle would convert from less thanto more than.

Abstract: Metallic nanowires have been widely studied in various fields due to its special properties such as electronic, optical and chemical. Conventional methods for the preparation of Cu nanowires are usually not accessible by using porous alumina templates due to restriction on using two-step anode oxidation, sputtering Au film, etc. In this paper, the porous alumina template was prepared by one-step anodization. An Al sheet was employed as cathode instead of a valuable Pt or graphite electrode. The Al substrate of alumina template was removed by using the concentrated hydrochloric acid/ethanol solution instead of a heavy metallic salt solution of SnCl₄, HgCl₂ or CuCl₂ used in documents. Cu nanowires were prepared in the porous alumina template by electro-deposition with moving cathode. Some of Cu nanowires were neatly assembled together to form a hemispherical structure and were protected from oxidation. The operations can reduce the cost and simplify the operation.

Abstract: Since transparent conducting oxides can be as a buttom layer of complex film electrodes, electrodeposition technique may produce ZnO films depending on variety conditions and modified surface layers of substrates in electrochemical procedures. Here we invested the structure and morphologies of ZnO films by using modified surface of the substrate-ZnO/ITO/polymer-PEN and ZnO doped Ga/ ITO/polymer-PEN.

Abstract: Fast growth of ZnO nanosheets on exfoliated tips of multiwalled carbon nanotube films were investigated by electrodeposition from zinc nitrate bath. Variation of electrodeposition time showed the presence of ZnO at only 25s. At 100s, the ZnO crystal size is dominated by the dimension of carbon nanotube patterns formed after wet. Longer depositions (240-480s) produced dense films but with smaller nanosheets.

Abstract: Zinc oxide (ZnO) presents several applications as piezoelectric transducers, photosensors, solar cells, electrochemical sensors, etc. Electrodeposition of zinc oxide (ZnO) thin films from aqueous solution of zinc nitrate has been deposited in graphenated low cost pencil graphite. The electrochemical graphene production at the tips was performed in a low cost DC source using concentrated sulfonitric solution. The tips were expanded in hydrogen plasma and treated by oxygen plasma to enhance its hydrophilicity. The posterior ZnO electrodeposition was highly efficient and the graphene functionalization contributes to overall electrochemical deposition mechanism.

Abstract: The Ni based alloys and composites synthesized by electro-deposition techniques were investigated in this paper. The co-deposition techniques for development of Ni-Co alloys, synthesis of oxide doped nanocomposites were analyzed. The hardness, wear resistance and corrosion resistance of different coatings: Ni, Ni-Co alloys, Ni-Fe₂O_3, Ni-Al₂O_3, Ni-Fe-BN, Ni-TiN composites were studied in detail. The Ni-Fe-BN and Ni-TiN showed more than 550 percent increase in hardness of stainless steel substrate. The Hardness was found to be about 600-1180Hv for Nitride impregnated coatings. These films also showed higher corrosion resistance in comparison to other Ni based alloy and composite coatings. The microstructural investigation of these alloys showed nanostructured rods and fibres in the deposited films.

Abstract: Electrochemical or electro co-deposition techniques have been used to deposit particles in metallic matrices to prepare composite coatings. The properties of the composite material can be improved by varying the type, size, amount and distribution of the incorporated particles. The effect factors of particles content in the coating were are presented in this review. The main focus is on the effect of surfactant, electrodeposition technology, zeta Potential and particles concentration in the bath on the content and distribution of co-deposited particles in the metal matrix.

Abstract: Mo-Ni coatings were prepared on Ni alloy by electrodeposition method. The effects of electrodeposition temperature, current density, stir speed and electrodeposition time on deposition rate and microhardness of Mo-Ni coating were researched, respectively. Deposition rate of Mo-Ni coating decreases with the increase of electrodeposition temperature in 35 °C ~ 60 °C. Deposition rate and microhardness of Mo-Ni coating increases with the increase of current density respectively in 15 A/dm² ~ 17.5 A/dm². Deposition rate and microhardness of Mo-Ni coating decreases with the increase of stir speed respectively in 200 r/min to 400 r/min. Deposition rate and microhardness of Mo-Ni coating decreases with the increase of electrodeposition time respectively in 30 min ~ 40 min. When electrodeposition parameters: temperature 35 °C, current density 17.5 A/dm², stir speed 200 r/mi, pH 5 and time 30 min, deposition rate and microhardness of Mo-Ni coatin are as high as 0.269 mg/ cm²·min and 502.4 HV respectively.