# How to prevent Ag2O from decomposing to Ag on Aluminum

I have silver oxide in an ink formulation. When I apply it (in small quantities) over aluminum and heat the resulting (to evaporate the solvent), the monovalent silver oxide seems to decompose to Ag. The temperature I am evaporating the solvent is around 30-40˚C. The decomposition of Ag2O to Ag occurs at a temperature over 200˚C. However, I am aware that aluminum is a good conductor of heat, so even though the temperature was only 30-40˚C, Ag2O could have deposed because the temperature on the aluminum surface could have been around (or higher than) 200˚C.

My question is, is there a way to solve this problem. How can I still use aluminum and not worry about decomposing Ag2O to Ag when evaporating the solvent? Do I have to further reduce the temperature and is this the only solution? I tried to research this concept but couldn't find anything.

Thank you so much for your help.

First, as you mention, $\ce{Ag2O}$ starts to decomposes from ≥200 °C. Measure the temperature of the aluminum substrate with an IR thermometer or attached thermocouple to be sure you stay well below that. You can substantially speed drying of the ink by lowering the air pressure, e.g. using an aspirator pump, perhaps eliminating need to heat the substrate.
You may also need to anodize the aluminum prior to printing to prevent chemical reaction with the $\ce{Ag2O}$ in the ink. Aluminum is much higher in the electromotive series and would rapidly replace silver in the oxide.