Bipolar membranes
A bipolar membrane comprising a first member comprising at least one anion exchange material; a second member comprising at least one cation exchange material, wherein the first member and the second member together form an interface junction; and disposed within the interface junction a first layer comprising a first water dissociation catalyst and a second layer comprising a second water dissociation catalyst, wherein the first water dissociation catalyst is different than the second water dissociation catalyst.
1. A bipolar membrane comprising a first member comprising at least one anion exchange material; a second member comprising at least one cation exchange material, wherein the first member and the second member together form an interface junction; and disposed within the interface junction a first layer comprising a first water dissociation catalyst and a second layer comprising a second water dissociation catalyst, wherein the first water dissociation catalyst is different than the second water dissociation catalyst.
2. The bipolar membrane of claim 1 , wherein the first water dissociation catalyst and the second water dissociation catalyst are each in the form of nanoparticles.
3. The bipolar membrane of claim 2 , wherein the first water dissociation catalyst contacting a surface of the anion exchange material is selected from NiO, Pd, PtIr or Ir, and the second water dissociation catalyst contacting a surface of the cation exchange material is selected from Fe(OH) 3 , RuO 2 , or IrO 2 .
4. The bipolar membrane of claim 1 , wherein at least a portion of the first water dissociation catalyst contacts a surface of the anion exchange material, and at least a portion of the second water dissociation catalyst contacts a surface of the cation exchange material.
5. The bipolar membrane of claim 1 , wherein the first member is an anion exchange membrane, and the second member is a cation exchange membrane.
6. The bipolar membrane of claim 5 , wherein the first water dissociation catalyst contacting a surface of the anion exchange material is selected from Pd, PtRu, PtIr, Ir, Rh, NiO, MnO 2 , Al 2 O 3 , SiO 2 , anatase TiO 2 , rutile TiO 2 , or Co 2 O 3 .
7. The bipolar membrane of claim 5 , wherein the second water dissociation catalyst contacting a surface of the cation exchange material is selected from RuO 2 , IrO 2 , anatase TiO 2 , rutile TiO 2 , Fe(OH) 3 , MnO 2 , Pt, SiO 2 , Sb:SnO 2 , SnO 2 , Co 2 O 3 , ZrO 2 , In 2 O 3 , Rh.
8. The bipolar membrane of claim 1 , wherein the first layer comprising the water dissociation catalyst and the second layer comprising the second water dissociation catalyst together have a total thickness of 0.02 to 1 μm.
9. The bipolar membrane of claim 1 , further comprising at least one additional layer comprising a different water dissociation catalyst disposed within the interface junction.
10. The bipolar membrane of claim 1 , wherein the first water dissociation catalyst is an inorganic water dissociation catalyst and the second water dissociation catalyst is an inorganic water dissociation catalyst.
11. The bipolar membrane of claim 1 , wherein the first water dissociation catalyst and the second water dissociation catalyst are independently selected from a metal, a metal oxide, a metal phosphide, or a metal sulfide.
12. The bipolar membrane of claim 1 , wherein the first water dissociation catalyst and the second water dissociation catalyst are independently selected from rutile TiO 2 , anatase TiO 2 , In 2 O 3 , indium tin oxide, Sb:SnO 2 , Sn 2 O 3 , Ir, IrO 2 , Pt, Ru, RuO 2 , Pd, Rh, MnO 2 , NiO, Al 2 O 3 , SiO 2 , ZnO 2 , ZrO 2 , Co 2 O 3 , Co:Fe 2 O 3 , Fe(OH) 3 , Pt—Ir(1:1), or Pt—Ru(1:1).
13. The bipolar membrane of claim 1 , wherein the first water dissociation catalyst contacting a surface of the anion exchange material is selected from NiO, Pd, PtIr or Ir, and the second water dissociation catalyst contacting a surface of the cation exchange material is selected from Fe(OH) 3 , RuO 2 , or IrO 2 .
14. The bipolar membrane of claim 1 , wherein the first water dissociation catalyst contacting a surface of the anion exchange material comprises NiO nanoparticles, and the second water dissociation catalyst contacting a surface of the cation exchange material comprises IrO 2 nanoparticles.
15. An electrochemical device comprising the bipolar membrane of claim 1 .
16. The electrochemical device of claim 15 , wherein the bipolar membrane is configured to promote dissociation of water.
17. A bipolar membrane comprising a first member comprising at least one anion exchange material having a first surface; a second member comprising at least one cation exchange material having a second surface, wherein the first member first surface and the second member second surface face each other to form an interface junction; and disposed within the interface junction is a plurality of individual layers, each individual layer comprising a different water dissociation catalyst wherein each individual layer of water dissociation catalyst functions within a predetermined pH range interval within a pH gradient extending between the first material first surface and the second material second surface.
18. The bipolar membrane of claim 17 , wherein the pH interval is 1 pH, 2 pH or 3 pH.
19. The bipolar membrane of claim 17 , wherein the first member is an anion exchange membrane, and the second member is a cation exchange membrane.
20. The bipolar membrane of claim 19 , wherein the different water dissociation catalysts are each in the form of nanoparticles are each independently selected from rutile TiO 2 , anatase TiO 2 , In 2 O 3 , indium tin oxide, Sb:SnO 2 , Sn 2 O 3 , Ir, IrO 2 , Pt, Ru, RuO 2 , Pd, Rh, MnO 2 , NiO, Al 2 O 3 , SiO 2 , ZnO 2 , ZrO 2 , Co 2 O 3 , Co:Fe 2 O 3 , Fe(OH) 3 , Pt—Ir(1:1), or Pt—Ru(1:1).