# Is there a selective wet etch of Bi2O3 Bismuth Oxide?

I'm looking for a wet etch of Bismuth Oxide that does not etch $\ce{Bi}$ itself.

There are obviously chemicals that etch $\ce{Bi2O3}$, but $\ce{Bi}$ is pretty fragile, so almost everything I've found that can etch $\ce{Bi2O3}$ also etches Bi, and usually more rapidly than the $\ce{Bi2O3}$ itself.

However, someone recently mentioned to me in passing that there was a chemical that could do this, but they didn't remember what it was.

Searching Google, I found this, but that's RIE -- not wet etching.

I've also read about people using $\ce{H2}$ gas to reduce the oxide back to $\ce{Bi}$, but again, not wet etching.

Does anyone have any idea? I know it's a specific and uncommon question.

• I saw on wikipedia that bismuth oxide is transformed to bismuth trioleate by a mixture of acetic anhydride and oleic acid. I'm not 100% sure but I doubt either of those materials does much to bismuth metal. Maybe that could be the basis of a wet etching? – Curt F. Jul 7 '15 at 21:36