Method of plating metal leafs and metal membranes
A method of plating a nanoporous metal membrane is provided where at least a portion of the nanoporous metal member is freely supported on the surface of a metal plating solution containing at least one platable metal and the surface of the metal plating solution is contacted with a plating initiator. The nanoporous metal membrane is allowed to contact the plating solution for a period of time effective to plate at least a portion of the nanoporous metal membrane with the at least one platable metal. The plating initiator is preferably hydrazine.
1 . An article which comprises:
a nanoporous metal membrane; and
a plating layer comprising at least one metal constituent formed on at least a portion of said nanoporous metal membrane.
2 . The article according to claim 1 , wherein said plating layer has a thickness of about 1 nm to about 5 nm.
3 . The article according to claim 1 , wherein said nanoporous metal membrane comprises gold.
4 . The article according to claim 1 , wherein said plating layer comprises at least one precious metal.
5 . The article according to claim 1 , wherein said plating layer comprises platinum.
6 . The article according to claim 1 , wherein said plating layer comprises at least one member selected from the group consisting of platinum, iridium, rhodium, ruthenium, palladium, cobalt and silver.
7 . The article according to claim 1 , wherein said plating layer comprises at least two metals.
8 . The article according to claim 1 , wherein said plating layer has a loading density of less than about 0.1 mg/cm 2 .
9 . The article according to claim 1 , wherein said plating layer has a loading density of less than about 0.05 mg/cm 2 .
10 . The article according to claim 1 , wherein said plating layer has a loading density of less than about 0.025 mg/cm 2 .
11 . The article according to claim 1 , wherein said plating layer has a loading density of about 0.005 mg/cm 2 .
12 . The article according to claim 1 , wherein said nanoporous metal membrane has a thickness of about 100 nm.
13 . The article according to claim 1 , wherein said nanoporous metal membrane has a thickness of less than about 500 nm.
14 . The article according to claim 1 , wherein said nanoporous metal membrane has a thickness of less than about 250 nm.
15 . The article according to claim 1 , wherein said nanoporous metal membrane has a thickness of less than about 100 nm.
16 . A membrane electrode assembly which comprises:
a polymer electrolyte membrane; and
a nanoporous metal membrane adhered to at least one surface of said polymer electrolyte membrane, wherein said nanoporous metal membrane comprises a plating layer comprising at least one metal formed on at least a portion thereof.
17 . The membrane electrode assembly according to claim 16 , wherein said polymer electrolyte membrane comprises a member selected from the group consisting of perfluorinated sulphonic acids and polystyrene sulfonate.
18 . The membrane electrode assembly according to claim 16 , wherein said nanoporous metal membrane comprises gold.
19 . The membrane electrode assembly according to claim 16 , wherein said plating layer comprises at least one precious metal.
20 . The membrane electrode assembly according to claim 16 , wherein said plating layer comprises platinum.
21 . The membrane electrode assembly according to claim 16 , wherein said plating layer comprises at least one member selected from the group consisting of platinum, iridium, rhodium, ruthenium, palladium, cobalt and silver.
22 . The membrane electrode assembly according to claim 16 , wherein said plating layer has a thickness of about 1 nm to about 5 nm.
23 . The membrane electrode assembly according to claim 16 , wherein said plating layer has a loading density of less than about 0.1 mg/cm 2 .
24 . The membrane electrode assembly according to claim 16 , wherein said plating layer has a loading density of less than about 0.05 mg/cm 2 .
25 . The membrane electrode assembly according to claim 16 , wherein said plating layer has a loading density of less than about 0.025 mg/cm 2 .
26 . The membrane electrode assembly according to claim 16 , wherein said plating layer has a loading density of about 0.005 mg/cm 2 .
27 . The membrane electrode assembly according to claim 16 , wherein said nanoporous metal membrane has a thickness of about 100 nm.
28 . The membrane electrode assembly according to claim 16 , wherein said nanoporous metal membrane has a thickness less about 500 nm.
29 . The membrane electrode assembly according to claim 16 , wherein said nanoporous metal membrane has a thickness of less than about 250 nm.
30 . The membrane electrode assembly according to claim 16 , wherein said nanoporous metal membrane has a thickness of less than about 100 nm.
31 . A fuel cell which comprises a membrane electrode assembly, wherein said membrane electrode assembly comprises a polymer electrolyte membrane; and a nanoporous metal membrane adhered to at least one surface of said polymer electrolyte membrane, and further wherein said nanoporous metal membrane comprises a plating layer comprising at least one metal formed on at least a portion thereof.
32 . The fuel cell according to claim 31 , wherein said polymer electrolyte membrane comprises a member selected from the group consisting of perfluorinated sulphonic acids and polystyrene sulfonate.
33 . The fuel cell according to claim 31 , wherein said nanoporous metal membrane comprises gold.
34 . The fuel cell according to claim 31 , wherein said plating layer comprises at least one precious metal.
35 . The fuel cell according to claim 31 , wherein said plating layer comprises platinum.
36 . The fuel cell according to claim 31 , wherein said plating layer comprises at least one member selected from the group consisting of platinum, iridium, rhodium, ruthenium, palladium, cobalt and silver.
37 . The fuel cell according to claim 31 , wherein said plating layer has a loading density of less than about 0.1 mg/cm 2 .
38 . The fuel cell according to claim 31 , wherein said plating layer has a loading density of less than about 0.05 mg/cm 2 .
39 . The fuel cell according to claim 31 , wherein said plating layer has a loading density of less than about 0.025 mg/cm 2 .
40 . The fuel cell according to claim 31 , wherein said plating layer has a loading density of about 0.005 mg/cm 2 .
41 . A method which comprises:
freely supporting at least a portion of a nanoporous metal membrane on a metal plating solution comprising at least one plating metal; and
contacting said metal plating solution with a reducing agent, thereby plating at least a portion of said nanoporous metal membrane with said at least one plating metal.
42 . The method according to claim 41 , wherein said reducing agent is hydrazine.
43 . The method according to claim 41 , wherein said at least one plating metal is selected from the group consisting of platinum, iridium, rhodium, ruthenium, palladium, cobalt, silver and combinations thereof.
44 . The method according to claim 41 , wherein said metal plating solution comprises Na 2 Pt(OH) 6 .
45 . The method according to claim 44 , wherein said metal plating solution comprises about 2 g/l to about 20 g/l of Na 2 Pt(OH) 6 .
46 . The method according to claim 41 , wherein said nanoporous metal membrane comprises gold.
47 . The method according to claim 41 , wherein said metal plating solution is contacted with a vapor phase reducing agent.
48 . The method according to claim 41 , wherein said metal plating solution comprises at least two plating metals.
49 . The method according to claim 41 , wherein said method further comprises contacting a portion of said nanoporous metal membrane with at least one thiol prior to freely supporting at least a portion of said nanoporous metal membrane on a metal plating solution.
50 . The method according to claim 49 , wherein said thiol is CH 3 (CH 2 ) 11 —SH or CH 3 (CH 2 ) 18 —SH or combinations thereof.
51 . The method according to claim 41 , wherein the surface of said nanoporous metal membrane is plated with said at least one plating metal substantially continuously.
52 . The method according to claim 41 , wherein said nanoporous membrane is entirely freely supported on said metal plating solution.
53 . A method which comprises:
contacting a nanoporous metal membrane with a metal plating solution comprising at least one plating metal; and
contacting said metal plating solution with a vapor phase reducing agent, thereby plating at least a portion of said nanoporous metal membrane with said at least one plating metal.
54 . The method according to claim 53 , wherein said reducing agent is hydrazine.
55 . The method according to claim 53 , wherein said at least one plating metal is selected from the group consisting of platinum, iridium, rhodium, ruthenium, palladium, cobalt, silver and combinations thereof.
56 . The method according to claim 53 , wherein said metal plating solution comprises Na 2 Pt(OH) 6 .
57 . The method according to claim 56 , wherein said metal plating solution comprises about 2 g/l to about 20 g/l of Na 2 Pt(OH) 6 .
58 . The method according to claim 53 , wherein said nanoporous metal membrane comprises gold.
59 . The method according to claim 53 , wherein the surface of said nanoporous metal membrane is plated with said at least one plating metal substantially continuously.
60 . The method according to claim 53 , wherein said metal plating solution comprises at least two plating metals.
61 . The method according to claim 53 , wherein said method further comprises contacting a portion of said nanoporous metal membrane with at least one thiol prior to contacting said nanoporous metal membrane with a metal plating solution.
62 . The method according to claim 61 , wherein said thiol is CH 3 (CH 2 ) 11 —SH, CH 3 (CH 2 ) 18 —SH or combinations thereof.
63 . The method according to claim 53 , wherein at least a portion of said nanoporous metal membrane is freely supported on said metal plating solution.
64 . The method according to claim 53 , wherein said nanoporous membrane is entirely freely supported on said metal plating solution.