Zn(Ac)2 + 2HOH = Zn(OH)2 + 2HAc

Addition of triethanolamine binds acetic acid. The equilibrium is shifted towards zinc hydroxide. He "sits" on your silica. Only then it will be heated heterogeneous of nanoparticles to obtain  zinc oxide.from hydroxide

Best regards

This might work, but keep in mind that both compounds can adsorb on the surface of the particles. “Without” water the ZnOwill form at RT in the reaction mixture. The acid can adsorb to the ZnO and the base to the SiO2. You can also think about using the other way starting with ZnO.

Article Synthesis and testing of ZnO nanoparticles for photo-initiat...

Hi,

Thank you for your very interesting answers,

Yuri :  So I will be able to cover silica with Zn(OH)2 with this method ! This can be suitable for what I want to do, i.e. a sacrificial template shell, as Zn(OH)2 can be washed easily with low concentrated HCl.

Michael : Ok, I need to to do this in methanol if I want to obtain ZnO coating instead of Zn(OH)2. I think I might prefer the Zn(OH)2 deposit as they are both diluted in HCl, and I only need this coating as a sacrificial template.

Best regards,

Julien

Be careful not dissolve the hydroxide. Even ZnO is soluble in avid medium.