Once again, this is going back to my laymen understanding, but since all matter, except for very rare special matter, has electrons, then it really just depends on what kind of material the MOFs fall under, which, if they were metallic or metal-like, then they might be capable of holding electrons in the right position to make new caoacitors with.

I hope somebody investigates it, and that it turns out that it works, and that we have new ultra capacitors to add to the new solid state battery technology in the next few years and the world looks a little bit brighter.