Well as I understand it the current scubbers in space craft are something use something like lithium hydroxide. As CO2 passes over the lithium hydroxide the result is Lithium Carbonate and Water. You could then use electrolysis to reclaim the Oxygen at that point. I believe the Lithium Carbonate can be transformed back into Lithium Hydroxide but you need to use the same amount of water to do so. I don't know if there is any pure electrolysis method of scrubbing CO2 directly