Morphology and Roughness of Silver Deposit Formed by Cementation at Various Temperatures in Pure Sulfuric Acid
✍ Scribed by Grzegorz D. Sulka; Marian Jaskuła
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- German
- Weight
- 991 KB
- Volume
- 89
- Category
- Article
- ISSN
- 0018-019X
No coin nor oath required. For personal study only.
✦ Synopsis
The morphology and surface roughness of silver (Ag) deposit formed on metallic copper (Cu) by cementation conducted in a 0.5M H 2 SO 4 solution was investigated at various temperatures above 258. The influence of the presence or absence of oxygen (O 2 ) on Ag morphology was studied at an initial Ag + concentration of 20 mg/dm 3 . An analysis of distribution diagrams of the surface height calculated from scanning-electron-microscope (SEM) top-view images was performed. The cementation reaction results in a non-homogeneous Ag deposit formed on the surface independently of the presence or absence of O 2 in solution. The Ag deposit covers Cu mainly with a uniform and compact layer with separated germs of predendrites, but also a huge fern-leaf-shaped and lycopodium-twigs-shaped dendrites appear occasionally on the surface. The presence of O 2 in the system and temperature do not affect significantly the morphology of Ag dendrite as well as a deposit formed on the smooth part of the surface. The roughness of surface with Ag cement varies with temperature only under aerobic conditions where the enhanced Cu corrosion increases the size of anodic sites. The results obtained from the surfaceheight-distribution diagrams constructed for anaerobic conditions showed that the reaction between Cu + and Ag + does not start in the bulk of the solution even at the highest studied temperature.