Method for producing compositions of nanoparticles on solid surfaces

Abstract

A method for producing nanoparticles on a substrate using a metal precursor in an ionic liquid and microwave heating is described. The composite compositions are useful as catalysts for chemical reactions, fuel cell, supercapacitor and battery components, and the like.

1 . A method for producing nanoparticles of metal deposited on a surface of a substrate which comprises: 
 (a) providing a solution of an ionic liquid in a reducing liquid solvent containing a precursor of the metal on the substrate; and    (b) exposing the metal precursor in the ionic liquid to microwaves so as to reduce the metal precursor to nanoparticles of the metal which are deposited on the substrate.    
     
     
         2 . The method of  claim 1  wherein the substrate has a surface which comprises carbon on which the nanoparticles of the metal are deposited.  
     
     
         3 . The method of  claim 2  wherein the carbon is a graphite.  
     
     
         4 . The method of  claim 2  wherein the carbon is as a carbon black particle.  
     
     
         5 . The method of  claim 2  wherein the carbon is as a nanotube.  
     
     
         6 . The method of  claim 2  wherein the carbon is a fiber.  
     
     
         7 . The method of  claim 2  wherein the carbon is a buckyball.  
     
     
         8 . The method of  claim 2  wherein the carbon has at least one nanodimension.  
     
     
         9 . The method of  claim 2  wherein the substrate is a nanoparticle which is less than 100 nanometers in at least one dimension.  
     
     
         10 . The method of  claim 1  wherein at least two of the metal precursors are provided in admixture in step (a).  
     
     
         11 . A composite composition which comprises a substrate having nanoparticles of a metal deposited thereon.  
     
     
         12 . The composition of  claim 11  wherein the nanoparticles of the metal are comprised of a noble metal alone or in combination with a transition metal.  
     
     
         13 . The composition of  claim 11  wherein the nanoparticles of the metal are comprised of any metal alone or in combination with any other metal.  
     
     
         14 . The composition of  claim 11  wherein the substrate is a nanoparticle having at least one dimension less than 100 nanometers.  
     
     
         15 . The composition of  claim 14  wherein the nanoparticle of the substrate comprises a carbon.  
     
     
         16 . The method of  claim 1  wherein the substrate has a surface which comprises a solid on which the nanoparticles of the metal are deposited.  
     
     
         17 . The composition of  claim 11  wherein the nanoparticles have been formed on the substrate by microwave irradiation of a precursor to the metal in an ionic liquid.