Electroplating uses to go wrong and need much practice. I wouldn't choose that for a short project.
If really electroplating, then I'd suggest Ni-Mo, Co-Mo and Ni-Co-Mo alloys. I haven't read about them, Mo has a redox potential very close to Ni and Co so hopefully it co-deposits easily, and with some luck, few % Mo improve a property of electrodeposited Ni and Ni-Co, like the hardness. Ni is among the easiest metals to deposit. The experiment needs some means to analyse the layer and preferably to measure a hardness (maybe a sewing needle suffices, hold with the fingers).
As a teen, I obtained a polymer from dry NaOH with Al chips poured in 1,1,1-trichloroethane. Room temperature and pressure, reaction started immediately. What elements does the polymer contain: C, H, O? I say no Cl from the odour when burning and from the density. I suspect a polyketone.
Is it chemistry? Replace water with a solid paraffin in a hot water bottle. Measure that the solidification of paraffin provides more heat than cooling water, and at a more constant temperature. That one is clearly useful.
Measure accurately the density of pure straight alkanes when solid at 77K, say C6 to C11. Check if any even-odd effect.