Electroplated composites activity

In electroplating processes, cinnamaldehyde is utili2ed as a hrightener (35). Other appHcations include its efficacy as an animal repellent (36), its use in compositions to attract insects (37), and demonstration of a positive antiflmgal activity (38). 

Extensive work has been devoted to aluminum electroplating in nonaqueous systems. Choosing appropriate bath compositions enables aluminum to be deposited at high efficiency and purity from nonaqueous electrolyte solutions. Comprehensive reviews on this matter have appeared recently in the literature [123,455], This work has led to the development of a number of commercial processes for nonaqueous electroplating of aluminum. The quality of the electroplated aluminum is very similar to that of cast metal. For instance, electrodeposited aluminum can be further anodized in order to obtain hard, corrosion resistive, electrically insulating surfaces. It is also possible to electroplate A1 on a wide variety of metal surfaces, including active metals (e.g., Mg, Al), nonactive metals, and steel. 

It is claimed (165) that a composite electroplated deposit of Co plus Mo, regardless of the alloy thickness, provides far from such an active deposit as is achieved by in situ addition of very small amounts of Co and Mo anionic species during cathodic Hj evolution where at least 200 mV of overpotential... 

The catalyst system was obtained by the electroplating of a Co-Ni-P film on a Cu sheet. The film had amorphous morphology. NiSO concentration in the bath affected the deposition rate and catalytic activity of the catalyst system. The optimum value was 0.01 M for NiSO concentration. At this condition, hydrogen production rate was observed as 3636 mL min Bcataiyst 30°C. The activation energy was 38 kJ mol Hor sodium borohydride hydrolysis in the presence of Co-Ni-P catalyst film. Films had two distinct areas which were outer spherical particles and inner layer. These areas depended on NiSO, concentration. Increase in NiSO, concentration led to a decrease in the outer spherical catalyst particles and micro-cracks. It was concluded that catalysts production inner layer increased whereas catalyst production on the outer particles decreased. NiSO concentration increase led to an increase in Ni and P amount in the catalyst composition. However, Co amount decreased. At the optimum concentration that is 0.01 M NiSO, the composition was 80.5 at% Co, 5.0 at% Ni and 14.5 at% P. Above this point, the deposition rate increased but catalytic activity decreased [58]. Therefore, it was demonstrated that better compositional configurations should be investigated. 

Owing to its catalytic activity, ruthenium dioxide (RuO,) is used extensively in industrial anodes for the chlor-alkali industry and the production of perchlorates. These ruthenium-dioxide-based anodes consist of a thin catalytic layer coated onto a titanium base metal. Iridium-dioxide-based anodes are used for the production of persulfates, in electroplating, and in hydrometallurgy for evolving oxygen. These composites anodes, because of their corrosion resistance in chloride-containing media or concentrated acids and their ability to decrease the overpotential of chlorine and oxygen evolution, are called by the trade name dimensionally stable anodes (acronyms DSA ). Other uses are in fuel cells electrodes electrocatalysts. 

The weak point in electroless plating is that the solution is inherently unstable (since it is this thermodynamic instability that allows the bath to operate). The composition of the bath must be such that it will be stable in the bulk of the solution, and reduction of the metal will only occur on the surface that has been activated. Thus, maintaining uniformity of the product can be much more of a challenge in electroless plating than in electroplating. Nevertheless, electroplat-... 

---