Reclaiming Copper from Sodium Persulfate #3: Bigger Graphite Anode
I tried scaling up the graphite anode by connecting several sketch pencil leads together.
I’ve done this using single strands of stranded copper wire to weave and knot the individual pencil leads together. Once tightly woven into place I’ve finalized everything by adding generous amounts of solder.
With regards to being able to use higher voltages this was no help (of course) and the pencil leads still disintegrated.
What I’ve learned:
- Fellow hacker reloc pointed out that the softer a pencil lead, the more graphite it contains. I’ve picked 2H leads for my tests so far and will switch to 6B leads (the softest I could find at short notice).
- What is going into solution depends on the voltage applied (potential) and which materials of lower potential are still there (if available, the lowest energy bond breaks first, even with high voltages).
- Documented potentials (see: Pauling electronegativity) are usually defined for platinum electrodes. If you’re using something else, you have to apply a correction value. Also thanks to reloc for helping out with all the theoretical science behind the experiment!