Coating surfaces with nanostructures

Patent metadata

Field	Value
Publication number	US-11414761-B2
Application number	US-201615349072-A
Country	US
Kind code	B2
Filing date	Nov 11, 2016
Priority date	May 12, 2014
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

At least one substrate part for is provided for coating. A first deposition is provided on the at least one support part as microstructuring of at least one first substance selected from the group consisting of rhenium, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, gold, tin, zinc, copper, cobalt, lead, nickel and alloys comprising these, from at least one first compound which provides the at least one first substance. A second deposition is provided on the at least one support part as a nano-structuring of at least one second substance chosen from a group comprising rhenium, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, gold and/or alloys thereof, of at least one second compound which provides the at least one second substance, in a solution.

First claim

The invention claimed is:

1. A process for coating a surface with nanostructures, comprising:
providing at least one support part to be coated;
providing a first deposition on the at least one support part of at least one first substance selected from the group consisting of rhenium, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, gold, and alloys comprising these, from at least one first compound which provides the at least one first substance, while using in addition a third compound in a same solution as the first compound, the third compound containing metal ions selected from the group consisting of acetates, sulfides, and sulfates of metals of groups IVb, Vb, VIb, IVa, and Va of the Periodic Table, wherein the first deposition is carried out by electrochemical methods, wherein the first deposition includes microstructuring;
before the first deposition and a second deposition, conditioning the support part by electrochemical methods selected from a group including potentiostatic methods, cyclic voltammetry, and current ramping, in a salt-containing, aqueous solution; and
after the first deposition, providing the second deposition of at least one second substance selected from the group consisting of rhenium, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, gold, and alloys comprising these, from at least one second compound which provides the at least one second substance, in a solution, wherein the second deposition is carried out by colloid synthesis, wherein the second deposition includes nanostructuring;
wherein the support part after the second deposition includes a plurality of hemispherical deposits and a plurality of nanotubes on the hemispherical deposits; and
a concentration of the at least one first substance in the first deposition is at least 10 times as high as that of the at least one second substance in the second deposition.

2. The process as claimed in claim 1 , wherein at least one reducing agent is used for the second deposition.

3. The process as claimed in claim 2 , wherein at least one of formic acids, borohydride, hydrazine, hydrogen, citric acid and derivatives thereof, ascorbic acid, ethanol, vitamin B2 and potassium bitartrate are used as the reducing agent.

4. The process as claimed in claim 1 , wherein an aqueous solution is used for the second deposition.

5. The process as claimed in claim 1 , wherein the concentration of the at least one second substance in the solution in the second deposition is at least 0.01 gram per liter.

6. The process as claimed in claim 2 , wherein the concentration of the at least one reducing agent in the second deposition is in a range from about 0.05 milliMolar to about 5 Molar.

7. The process as claimed in claim 1 , wherein the concentration of the at least one first substance in the first deposition is at least 0.1 gram per liter.

8. The process as claimed in claim 1 , wherein at least one of the at least one first compound and the at least one second compound is selected from the group consisting of hexachloro or tetrachloro compounds, phosphates, sulfates, oxides, nitrates, halogens, carbonyls, acetates, cyanides, complex salts and oxygen- and chlorine-containing hydrogen acids of the at least one first substance and second substance.

9. The process as claimed in claim 1 , wherein the second deposition is carried out over a period of at least one hour.

10. The process as claimed in claim 1 , wherein the first deposition is carried out in a period of from about one minute to about 60 minutes.

11. The process as claimed in claim 1 , wherein the support part is provided with at least one third substance in the polycrystalline state before the first deposition.

12. The process as claimed in claim 1 , wherein the support part consists of a material selected from the group consisting of glass, metals, semiconductors, polymers and PEM.

13. The process as claimed in claim 1 , wherein conditioning the support part by electrochemical methods occurs until identically shaped cyclic voltammograms or current ramps are repeatedly attained.

14. The process as claimed in claim 1 , wherein the at least one support part before the first deposition is nonconductive and has an electrically conductive coating.

15. The process as claimed in claim 1 , further comprising, before the first deposition, applying a nonconductive coating to the at least one support part, and then removing the nonconductive coating in subregions of the at least one support part, wherein a surface of the at least one support part exposed by removing the nonconductive coating is electrically conductive.

16. The process as claimed in claim 15 , wherein removing the nonconductive coating is performed by etching.

17. The process as claimed in claim 1 , further comprising, during the second deposition, providing at least one reducing agent, wherein a concentration of the at least one reducing agent is at least 100 times as high as a concentration of the at least one second substance.

18. The process as claimed in claim 1 , wherein the first substance is platinum, and the second substance is platinum.

19. The process as claimed in claim 1 , wherein the support part between the first deposition and the second deposition includes the hemispherical deposits and lacks the nanotubes.

Assignees

• Univ Freiburg Albert Ludwigs

Inventors

• Daubinger Patrick
• Kieninger Jochen
• Urban Gerald

Classifications

• Y02E60/50

  Fuel cells · CPC title

• C23C18/44

  using reducing agents · CPC title

• C25D5/605

  Surface topography of the layers, e.g. rough, dendritic or nodular layers · CPC title

• C25D5/10

  Electroplating with more than one layer of the same or of different metals (for bearings C25D7/10) · CPC title

• C23C18/1653

  Two or more layers with at least one layer obtained by electroless plating and one layer obtained by electroplating · CPC title