I am trying to work out a method of producing hydrogen gas (H2) cheaply. What I have so far is an electrolytic cell with carbon electrodes from a dry-cell battery powered by an A/C-D/C wall converter with output from 1.5V to 12V. I plan on using distilled water, but I don't want to rely on the water self-ionizing to split the molecules as this would take a VERY long time. The electrolytes I've looked at so far are sulfuric acid (H2SO4), hydrochloric acid (HCl), potassium hydroxide (KOH), and sodium hydroxide (NaOH). I'd like to use something relatively cheap and unlikely to produce poisonous gases (ie, Cl2) and production of oxygen would be a plus. Any suggestions?