Sciencemadness Discussion Board

Copper powder from CuSO4 + ascorbic acid - what ratio is needed of Asc Acid & what's left over - H2SO4?

RogueRose - 27-7-2020 at 16:17

I tried a small test run of this reaction by using filtered vitamin C pills and I got some really nice Cu powder. Nothing formed until I got the solution boiling and the first run through I stopped with a little liquid left but a fair amount of CuSO4 crystals formed upon drying, so I added water and heated again until it was almost dry and it seemed that most/all of the water had boiled off, but there was still a greenish/brown solution left barely covering the bottom. I also noticed that the vapor started to smell a little different towards the end and I suspected that I might be left with H2SO4 as IDK how this reaction is formed and where the SO4 goes during the reaction.

I'm trying to figure out what is left over after boiling and how to seperate the powder and solution and what to do with it. It is still acidic, which I figured it had to be.

Also, does anyone have any suggestions on the ratio's of ascorbic acid to CuSO4 to use? I've seen this reaction done with CuCl2 but the amounts of ascorbic acid were incredibly high and I know I used MUCH less (maybe 10% of what was suggested) for my reaction and it seemed to work well. I did get some pure powder which I'm going to try and was wondering if I could add it as powder or if I should dissolve it into a solution first.

Now I just need to figure out a way to filter this stuff b/c it goes through most of my filter papers until it is completely clogged up and so much gets trapped in it.


old school - 28-9-2020 at 04:30

Try using a centrifuge to separate it.

Tsjerk - 28-9-2020 at 06:33

Dehydroascorbic acid is formed, it donates two electrons.

Bedlasky - 28-9-2020 at 07:48

Use CuSO4 + Fe and boil it for a while. This is much cheaper way how to make copper powder. Another alternative is CuSO4 + HCl + Al.

valeg96 - 28-9-2020 at 07:51

I did it this spring with about 1L of saturated copper nitrate solution and around 200+ g of ascorbic acid. The copper you get with this method is a disgusting superfine orangeish/maroon powder, and can't be properly washed or filtered with home tools. I decanted it with liters and liters of water, until I gave up, filtered it all on multiple funnels and shoved it in the oven. Since I didn't especially need metallic copper but just wanted to recover copper in any form I let it combust in the oven (it burns like steel wool and got superfine black CuO.

TriiodideFrog - 29-9-2020 at 04:17

What a coincidence! I just tried the experiment before I came online. The ascorbic acid remained at 1.2 M while the copper sulfate concentration was varied to achieve 12:1, 6:1, and 3:1. i am still waiting for the results. Here is another thread on the topic, if it can help you :http://www.sciencemadness.org/talk/viewthread.php?tid=31113 :)

njl - 29-9-2020 at 05:04

How did you measure concentrations?

RogueRose - 29-9-2020 at 17:17

I can testify that the copper particles are incredibly small. My biggest problem was figuring out how to add the solutions. Should I add the CuSO4 to an ascorbic acid solution, or the opposite? Also, it seems that heat is needed for this to work and I found that bubbling was a major issue but I did use Vit C tablets dissolved & filtered, so maybe there was something in there.

I seem to recall the CuSO4 solution was supposed to turn green when the ascorbic acid (AA) was added, I found that it did but it quickly reverted back, and I don't think I was short on the AA.

In doing this research I also came across some method to make nano CuO and maybe nano Cu2O and I seem to recall it was done by passing CO or H2 over the copper salt (I think CuSO4). If anyone remembers the method on how to make nano CuO or Cu2O, I'm be interested in that as well

TriiodideFrog - 30-9-2020 at 22:51

My CuSO4 Solution did turn green, but there also seems to be something else in the Vitamin C pills as after a day the solution became unclear.

SaccharinSlayer157 - 1-10-2020 at 14:05

Here's a good video by chemplayer on the topic

https://www.bitchute.com/video/cMo36tADFb3v/

TriiodideFrog - 2-10-2020 at 18:24

I tried another method by just letting the copper precipitate. It is really slow and the copper is more reddish than normal. The solution also turned a really dark murky green.