Diffusion Panel Placement

I'm going to be building my own diffusion panels. Unfortunately where I'd like to place them wall hanging is not an option, not to mention they'll be heavy because they'll be wood. If the panels are just sitting atop a stand next to the wall as opposed to being attached to the wall will they work as they should?

Yes. Some manufactures offer stands as an option with their diffusion panels. I have some wall mounted behind my listening chair and some on the front wall on a mantle. They are heavy and you need to be very careful about the possibility of having them knocked over. A safety tether to the wall or something would be a good idea.
PS. Check the pic for Acapella High Violon in my system for a current system view. Also Core tweek toward the bottom of the page. (I'm a dealer)