Sciencemadness Discussion Board

Black Phosphorus Sources

Nitrous2000 - 8-2-2021 at 09:53

Hi folks,

I'm looking at battery development and have come across some literature involving phosphorus, specifically black phosphorus.

I'm having trouble sourcing this at anything approaching a reasonable cost. In the alternative, red phosphorus can be converted to black phosphorus.

Occasionally, red phosphorus shows up on eBay but is there any reliable source for this? I appreciate the DEA / watched chemicals list implications but I'm in Canada and the paperwork might be a little easier here. It's still a carefully controlled substance, even in Canada.

Thanks
Doug

njl - 8-2-2021 at 09:58

https://sci-hub.st/http://dx.doi.org/10.1039/C9TA13441G

unionised - 8-2-2021 at 11:11

Quote: Originally posted by njl  
https://sci-hub.st/http://dx.doi.org/10.1039/C9TA13441G

That's interesting,
I wonder if anyone has tried using this
https://en.wikipedia.org/wiki/Diethylenetriamine
as the solvent, since it has a higher boiling point and wouldn't need an autoclave.

pip - 9-2-2021 at 09:37

How much red phosphorus would you need? The availability of a few grams is doable, a kilo probably not.

Nitrous2000 - 9-2-2021 at 10:58

Quote: Originally posted by pip  
How much red phosphorus would you need? The availability of a few grams is doable, a kilo probably not.



50-100grams was my guess..
If the conversion goes well... I would have to make a more formal arrangement.

I'm about half way through my vacuum oven.... need a ramp PID
If you're interested, might get a sample of the black out of the deal :) (a gift, not a trade :) )

Thanks,
Doug

itsallgoodjames - 9-2-2021 at 11:45

Quote: Originally posted by pip  
How much red phosphorus would you need? The availability of a few grams is doable, a kilo probably not.


Where would one get those few grams of red phosphorus? For making haloalkanes, I've had to resort to using huge amounts of matchbox strikers, which isn't exactly the purest.

Black Phosphorus Sources

Nitrous2000 - 9-2-2021 at 11:49

yes, matches are not a practical source for making black phosphorus :)

Doug

DraconicAcid - 9-2-2021 at 13:42

Quote: Originally posted by unionised  
Quote: Originally posted by njl  
https://sci-hub.st/http://dx.doi.org/10.1039/C9TA13441G

That's interesting,
I wonder if anyone has tried using this
https://en.wikipedia.org/wiki/Diethylenetriamine
as the solvent, since it has a higher boiling point and wouldn't need an autoclave.


I may be wrong, but don't you need the autoclave for the pressure to make the black phosphorus?

clearly_not_atara - 9-2-2021 at 14:42

DraconicAcid: Black phosphorus is the thermodynamically stable allotrope of phosphorus at standard conditions. However, the free energy advantage vs. red phosphorus is so small, and the activation energy so large, it's basically the phosphorus equivalent of making diamond. Due to thermodynamics, any process capable of depositing BP crystals should make them at any pressure...
Quote: Originally posted by njl  
https://sci-hub.st/http://dx.doi.org/10.1039/C9TA13441G

That's a ridiculously huge improvement over the old methods. Except maybe "dissolved in molten bismuth", nothing we discussed in the old thread just four years ago comes close to being that simple. Dan Vizine and Fery were talking about building special-purpose distillation apparatuses for this:

http://www.sciencemadness.org/talk/viewthread.php?tid=12196

DraconicAcid - 9-2-2021 at 15:56

Thanks for the correction.