Anneal zinc foils at 300 degrees Celsius for 5 hours in the presence of argon gas.
Clean the zinc foils using acetone. Pour acetone into an ultrasonic bath and add the zinc foils. Turn the ultrasonicator on to expose the zinc and acetone to continuous vibrations. Pour out the acetone, wash the zinc with ethanol and dry it with nitrogen gas.
Set up for anodizing. Pour phosphoric acid into a beaker, or glass cell, if available. Place the two-electrode setup into the phosphoric acid. Connect the zinc sheets to one of the electrode terminals. Zinc is the "working" electrode, which is connected to the power source and is responsible for delivering voltage into the phosphoric acid. Connect the platinum, the counter electrode, to the other electrode terminal. Platinum will work to balance or remove the charge contributed by zinc. Add a stir bar to the beaker or glass cell and place it on a stir plate. Stir the setup at a constant rate over the duration of the anodizing procedure.
To verify and quantify anodization, use a scanning electron microscope to quantify the sizes of the pores formed on the surface as a result of step 3.