Method of producing catalytic material for fabricating nanostructures
View Patent ↗Methods of fabricating nano-catalysts are described. In some embodiments the nano-catalyst is formed from a powder-based substrate material and is some embodiments the nano-catalyst is formed from a solid-based substrate material. In some embodiments the substrate material may include metal, ceramic, or silicon or another metalloid. The nano-catalysts typically have metal nanoparticles disposed adjacent the surface of the substrate material. The methods typically include functionalizing the surface of the substrate material with a chelating agent, such as a chemical having dissociated carboxyl functional groups (—COO), that provides an enhanced affinity for metal ions. The functionalized substrate surface may then be exposed to a chemical solution that contains metal ions. The metal ions are then bound to the substrate material and may then be reduced, such as by a stream of gas that includes hydrogen, to form metal nanoparticles adjacent the surface of the substrate.
1. A method of fabricating a nano-catalyst comprising:
(a) washing a silicon metalloid substrate material with one or more materials selected from the group consisting of ethanol, acetone, chloroform, and water to form a treated substrate material;
(b) contacting the treated substrate material with nitric acid to provide an activated substrate material having an active silicon surface;
(c) contacting the activated substrate material with a complexing agent to provide a complexed substrate material having functionalized groups on the active silicon surface;
(d) contacting the complexed substrate material with metal ions wherein at least a portion of the metal ions are bound to the complexed substrate material; and
(e) contacting the metal ions bound to the complexed substrate material with a reducing atmosphere to form the nano-catalyst as metal nanoparticles on the substrate material.
2. The method of claim 1 wherein the substrate material comprises a silicon wafer.
3. The method of claim 1 wherein the complexing agent comprises a chelating agent.
4. The method of claim 1 wherein the complexing agent comprises a coupling agent.
5. The method of claim 1 wherein the complexing agent comprises a mixture of chloroform and a silane compound.
6. The method of claim 1 wherein the functionalized groups on the active silicon surface comprises carboxyl functional groups.
7. The method of claim 1 wherein the reducing atmosphere is at a temperature of about 600° C.
8. A method of fabricating a nano-catalyst comprising:
(a) contacting a silicon metalloid substrate material with nitric acid to provide an activated substrate material having an active silicon surface;
(b) contacting the activated substrate material with a complexing agent to provide a complexed substrate material having functionalized groups on the active silicon surface;
(c) contacting the complexed substrate material with metal ions wherein at least a portion of the metal ions are bound to the complexed substrate material; and
(d) contacting the metal ions bound to the complexed substrate material with a reducing atmosphere to form the nano-catalyst as metal nanoparticles on the substrate material.