RogueRose - 27-3-2017 at 10:06
I'm going to try to make some Fe2O3 via electrolysis and I've seen videos and write ups that use NaCl or NaHCO3 and was wondering which would be best.
I would suspect that using salt might produce Cl2 gas though not sure. With the bicarb I would think that H2 would be produced.
As far as voltage, I can generate anything from 5v - 170v DC. If rust is desired and I'm basically looking for destructive electrolysis of the metal,
is there any reason not to to use a higher current density?
Setup is a 5 gallon bucket and I'm planning on using cast iron for the annode and cathode. Is there any reason to use something else for the cathode
like carbon/graphite plate?
Will this process produce any Fe3O4? I made some iron oxide with steel wool and bleach and got a mix of both Fe2O3 and Fe3O4 (maybe 6:1) but since
the hypochlorite is a strong oxidizer I think this may have something to do with the results.
Zyklon-A - 27-3-2017 at 16:04
I used bicarb and chloride (like 3/1) but I'm not sure how/if this is really better than anything else.
Iron (II, III) oxide can be made by passing water vapor over red hot iron fillings or steel wool.
ferrousexplosive - 12-7-2017 at 19:38
I have done several pounds in the course of the past years, I personally don´t need the oxide in a great scale, i have almost always used sodium
chloride as electrolite, for the cell i use a 1 liter plastic jar and a 6v 0,5 amp current 
idont really have another way to get more power than that. About chlorine production it happens, but only in small quantities even at
great scale, i recomend to have a inverted funnel and a hose to drive out and safely all the gases generated (Mainly hydrogen)
Sodium bicarbonate is good if you dont have anything else, however if you want a destructive process to completely disolve your anode i think it would
be interesting to apply constant heat to the solution, between 50-60 C to increase the conductivity, i used sodium hydroxide as electrolyte, the
result was the cathode producing oxygen and lowering greatly the production of iron hydroxide
Tellurium - 12-7-2017 at 21:40
Wouldn't it be better to use an acidic electrolyte and then add some base to it after the electrolysis?
I always noticed, that the conductivity of Iron electrodes drop in basic medium, I think because of the oxide layer covering the surface area.
However if you use enough power to get a nice and strong gas production the oxide layer flakes of faster, so you wouldn't have that much of a problem
with it, but you're wasting power because of electrolysis of water.
ferrousexplosive - 13-7-2017 at 18:05
I am relatively new to chemistry, it is posible to make electrolysis in acidic media without creating the salt of iron and the acid?
From my understanding, i would be created let´s say iron sulphate FeSO4 then you add the base like NaOH it wouls result Iron hydroxide and sodium
sulfate
FeSO4 + 2 NaOH → Fe(OH)2 + Na2SO4
right? the sodium salt would stay in solution while the iron hydroxide precipitates and can be filtered.