Method to produce noble metal nanocomposites

Abstract

The method for producing noble metal nanocomposites involves reducing noble metal ions (Ag, Au and Pt) on graphene oxide (GO) or carbon nanotubes (CNT) by using Artocarpus integrifolia leaves extract as a reducing agent. As synthesized MNPs/GO and MNPs/CNT composites have been characterized using X-ray diffraction (XRD), transmission electron microscope (TEM) imaging, and energy dispersive X-ray spectroscopy (EDX). The TEM images of prepared materials showed that the nanocomposites were 1-30 nm in size with spherical nanoparticles embedded on the surface of GO and CNT. This synthetic route is easy and rapid for preparing a variety of nanocomposites. The method avoids use of toxic chemicals, and the prepared nanocomposites can be used for biosensor, fuel cell, and biomedical applications.

1 . A method for producing noble metal nanocomposites, comprising the steps of:
 functionalizing carbon nanotubes;   preparing an aqueous solution of the functionalized carbon nanotubes;   adding an aqueous solution of a salt of a noble metal to the solution of the functionalized carbon nanotubes to form a complex of the functionalized carbon nanotubes and the noble metal ion in aqueous solution; and   reducing the noble metal ion on the carbon nanotubes by adding an extract of  Artocarpus integrifolia  leaves to the aqueous solution of the noble metal ion-functionalized carbon nanotubes complex, thereby forming a composite of nanoparticles of the reduced noble metal on the functionalized carbon nanotubes the nanoparticles being embedded on a surface of the carbon nanotubes.   
     
     
         2 . (canceled) 
     
     
         3 . The method for producing noble metal nanocomposites according to  claim 1 , wherein the carbon nanotubes are functionalized by oxidation in an acid, the oxidation including refluxing the carbon nanotubes with the acid. 
     
     
         4 . The method for producing noble metal nanocomposites according to  claim 1 , wherein the noble metal is selected from the group consisting of platinum, gold, and silver. 
     
     
         5 . The method for producing noble metal nanocomposites according to  claim 1 , wherein the noble metal is platinum and the nanoparticles of the reduced noble metal have a particle size between 1 nm and 3 nm. 
     
     
         6 . The method for producing noble metal nanocomposites according to  claim 1 , wherein the noble metal is gold and the nanoparticles of the reduced noble metal have a particle size between 10 nm and 20 nm. 
     
     
         7 . The method for producing noble metal nanocomposites according to  claim 6 , wherein the nanoparticles are substantially spherical. 
     
     
         8 . The method for producing noble metal nanocomposites according to  claim 1 , wherein the noble metal is silver and the nanoparticles of the reduced noble metal have a particle size between 20 nm and 30 nm. 
     
     
         9 . The method for producing noble metal nanocomposites according to  claim 1 , wherein said step of adding the aqueous solution of a salt of a noble metal to the solution of the functionalized carbon nanotubes comprises adding the aqueous solution of a salt of a noble metal drop-wise. 
     
     
         10 . The method for producing noble metal nanocomposites according to  claim 1 , further comprising the step of preparing the extract of  Artocarpus integrifolia  leaves, including the steps of:
 washing  A. integrifolia  leaves several times with deionized water;   chopping the washed leaves;   stirring the chopped leaves in distilled water at 95° C. for about 5 minutes to obtain the leaf extract; and   filtering to remove the chopped leaves from the leaf extract.   
     
     
         11 . The method for producing noble metal nanocomposites according to  claim 1 , wherein the nanoparticles of the noble metal are uniformly dispersed on the functionalized carbon nanotubes. 
     
     
         12 . A platinum-graphene oxide nanocomposite prepared according to the method of  claim 18 . 
     
     
         13 . A platinum-carbon nanotube nanocomposite prepared according to the method of  claim 1 . 
     
     
         14 . A gold-graphene oxide nanocomposite prepared according to the method of  claim 18 . 
     
     
         15 . A gold-carbon nanotube nanocomposite prepared according to the method of  claim 1 . 
     
     
         16 . A silver-graphene oxide nanocomposite prepared according to the method of  claim 18 . 
     
     
         17 . A silver-carbon nanotube nanocomposite prepared according to the method of  claim 1 . 
     
     
         18 . A method for producing noble metal nanocomposites, comprising the steps of:
 preparing an aqueous solution of graphene oxide;   adding an aqueous solution of a salt of a noble metal to the solution of the graphene oxide to form a complex of the graphene oxide and the noble metal ion in aqueous solution; and   adding an extract of  Artocarpus integrifolia  leaves to the aqueous solution of the noble metal ion-graphene oxide complex in order to reduce the noble metal ion, thereby forming a composite of nanoparticles of the reduced noble metal on the graphene oxide.