For a future project, I put together a graphite gas diffusion electrode. Normally, a gas diffusion electrode would require impregnation with a catalyst like platinum (which I may try in the future if I decide to build a fuel cell), however, the synthesis we'll be following doesn't call for a catalyst on the electrode, just a graphite surface.
To make the electrode, I take a graphite rod and drill a hole down the centre. Pressurising this cavity with air allows gas to flow through the porous electrode and into the solution, creating a large amount of surface area to connect the gas, electrode, and electrolyte. Hopefully this electrode allows for electrochemical reactions involving reactants in the gas phase.