Air driven skimmers have been used for along time in the hobby so you are good to go as far as "concept". Several issues with your current design however. The neck is way to long to be an effective skimmer and the position is not correct where it enters the chamber to ever work properly.
You need to decrease the neck length by probably half if not more. The PVC
should not extend into the "reaction chamber as it does not allow a smooth transition for the skinmate to move upwards it will get caught in your current design and never will be able to move up and out into the collection cup. You also need to decrease the body height to limit the head space of your chamber even more in my opinion.