Crystalline boron nitride aerogels
This disclosure provides methods and materials related to boron nitride aerogels. For example, one aspect relates to a method for making an aerogel comprising boron nitride, comprising: (a) providing boron oxide and an aerogel comprising carbon; (b) heating the boron oxide to melt the boron oxide and heating the aerogel; (c) mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide; and (d) converting at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride. Another aspect relates to a method for making an aerogel comprising boron nitride, comprising heating boron oxide and an aerogel comprising carbon under flow of a nitrogen-containing gas, wherein boron oxide vapor and the nitrogen-containing gas convert at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride.
1. A method for making an aerogel comprising boron nitride, comprising:
(a) providing boron oxide and an aerogel comprising carbon;
(b) heating the boron oxide to melt the boron oxide and heating the aerogel;
(c) mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide; and
(d) converting at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride.
2. The method of claim 1 , wherein the aerogel comprising carbon comprises sp 2 carbon.
3. The method of claim 1 , wherein the aerogel comprising carbon is a graphene aerogel.
4. The method of claim 1 , wherein the boron oxide is heated to a temperature of at least about 1500° C.
5. The method of claim 1 , wherein the boron oxide is heated to a temperature of about 1600° C. to about 1800° C.
6. The method of claim 1 , wherein flow rate of the nitrogen-containing gas is about 1000 sccm to about 2000 sccm.
7. The method of claim 1 , wherein the nitrogen-containing gas is N 2 .
8. The method of claim 1 , wherein the aerogel comprising carbon is substantially free of contact with liquid boron oxide.
9. The method of claim 1 , wherein at least about 95 atomic percent of the carbon is converted to boron nitride.
10. The method of claim 1 , wherein the aerogel comprising boron nitride obtained has an ordered crystalline structure comprising atomic layers of hexagonal boron nitride laying on top of one another, and wherein atoms contained in a first layer are superimposed on atoms contained in a second layer.
11. A method for making an aerogel comprising boron nitride, comprising heating boron oxide and an aerogel comprising carbon under flow of a nitrogen-containing gas, wherein boron oxide vapor and the nitrogen-containing gas convert at least a portion of the carbon to boron nitride to obtain the aerogel comprising boron nitride.
12. The method of claim 11 , wherein the aerogel comprising carbon comprises sp 2 carbon.
13. The method of claim 11 , wherein the aerogel comprising carbon is a graphene aerogel.
14. The method of claim 11 , wherein the boron oxide is heated to a temperature of at least about 1500° C.
15. The method of claim 11 , wherein the boron oxide is heated to a temperature of about 1600° C. to about 1800° C.
16. The method of claim 11 , wherein flow rate of the nitrogen-containing gas is about 1000 sccm to about 2000 sccm.
17. The method of claim 11 , wherein the nitrogen-containing gas is N 2 .
18. The method of claim 11 , wherein the aerogel comprising carbon is substantially free of contact with liquid boron oxide.
19. The method of claim 11 , wherein at least about 95 atomic percent of the carbon is converted to boron nitride.
20. The method of claim 11 , wherein the aerogel comprising boron nitride obtained has an ordered crystalline structure comprising atomic layers of hexagonal boron nitride laying on top of one another, and wherein atoms contained in a first layer are superimposed on atoms contained in a second layer.