the thing with electrolizing water is that it also gives of hydrogen and there isnt away really telling which on is which unless you put a flame in one if it goes pop then its hydrogen but if you blow out the flame and put it in one and it reignites then its oxygen but by that time you have used it all and you dont get that much oxygen through electrolysis, its not a very good way of getting it, but anyway yes i think that would make lead oxide make sure you seal the lead and oxygen in a bottle to make sure it fully reacts