Production method for a metal nanostructure using an ionic liquid

Abstract

The present invention provides a method of forming metal nanostructures, and, more particularly, a method of uniformly forming various shapes of nanostructures, such as cubic or octahedral nanoparticles, nanowires and the like, using ionic liquid in a polyol reduction reaction in which metal salts are used as precursors.

1 . A method of forming various shapes of metal nanostructures, comprising the steps of:
 mixing an ionic liquid, a metal salt and a reducing solvent to form a mixture; and   reacting the mixture.   
     
     
         2 . The method according to  claim 1 , wherein the shape of the metal nanostructure is determined by chemical bonding between a cation and an anion constituting the ionic liquid. 
     
     
         3 . The method according to  claim 2 , wherein the ionic liquid containing a sulfur compound anion such as an alkyl sulfate anion (RSO 4   − ) or alkyl sulfonate anion (RSO 3   − ) is used to form a one-dimensional metal nanostructure such as a nanowire, the ionic liquid containing a halide anion is used to form a three-dimensional metal nanostructure, the ionic liquid containing a chlorine anion (Cl − ) is used to form a cubic metal nanostructure, and the ionic liquid containing a bromine anion (Br) is used to form an octahedral metal nanostructure. 
     
     
         4 . The method according to  claim 3 , wherein the ionic liquid is a compound including an organic cation and an organic or inorganic anion, and is a monomolecular compound or a polymeric compound. 
     
     
         5 . The method according to  claim 4 , wherein the ionic liquid includes an imidazolium-based ionic liquid represented by Formula 1A below and a pyridinium-based ionic liquid represented by Formula 1B below: 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are identical to or different from each other, are each independently selected from hydrogen and a hydrocarbon group of C1-C16, and includes a hetero atom; and X −  is an anion of the ionic liquid, 
       
       
         
           
           
               
               
           
         
         wherein R 3  and R 4  are identical to or different from each other, are each independently selected from hydrogen and a hydrocarbon group of C1-C16, and includes a hetero atom; and X −  is an anion of the ionic liquid. 
       
     
     
         6 . The method according to  claim 4 , wherein the anion of the ionic liquid is any one selected from Br − , Cl − , I − , BF 4   − , PF 6   − , ClO 4   − , NO 3   − , AlCl 4   − , Al 2 Cl 7   − , AsF 6   − , SbF 6   − , CH 3 COO − , CF 3 COO − , CH 3 SO 3   − , C 2 H 5 SO 3   − , CH 3 SO 4   − , C 2 H 5 SO 4   − , CF 3 SO 3   − , (CF 3 SO 2 ) 2 N − , (CF 3 SO 2 ) 3 C − , (CF 3 CF 2 SO 2 ) 2 N − , C 4 F 9 SO 3   − , C 3 F 7 COO − , and (CF 3 SO 2 )(CF 3 CO)N − . 
     
     
         7 . The method according to  claim 1 , wherein the metal salt is composed of a metal cation and an organic or inorganic anion, and is any one selected from AgNO 3 , Ag(CH 3 COO) 2 , AgClO 4 , Au(ClO 4 ) 3 , PdCl 2 , NaPdCl 4 , PtCl 2 , SnCl 4 , HAuCl 4 , FeCl 2 , FeCl 3 , Fe(CH 3 COO) 2 , CoCl 2 , K 4 Fe(CN) 6 , K 4 Co(CN) 6 , K 4 Mn(CN) 6 , K 2 CO 3 . 
     
     
         8 . The method according to  claim 1 , wherein the reducing solvent is a solvent having two or more hydroxy groups in a molecule thereof, such as a diol, a polyol, a glycol or the like, and is any one selected from ethyleneglycol, 1,2-propyleneglycol, 1,3-propyleneglycol, glycerin, glycerol, polyethyleneglycol, and polypropyleneglycol. 
     
     
         9 . The method according to  claim 1 , wherein, in a mixing ratio of the ionic liquid, metal salt and reducing solvent, the metal salt has a concentration of 0.01˜1 M based on the reducing solvent, and the ionic liquid (its repetitive unit when it is a polymeric ionic liquid) has a concentration of 0.001˜1 M based on the reducing solvent. 
     
     
         10 . The method according to  claim 1 , wherein, in addition to the ionic liquid, metal salt and reducing solvent, a nitrogen compound represented by Formula 2A below or a sulfur compound represented by Formula 2B below is used as an additive: 
       
         
           
           
               
               
           
         
         wherein R 5 , R 6 , R 7  and R 8  are identical to or different from each other, are each independently selected from hydrogen and a hydrocarbon group of C1-C20, and includes a hetero atom; and Y −  is an organic or inorganic anion, 
       
       
         
           
           
               
               
           
         
         wherein R is a monomolecular or polymeric hydrocarbon group, and includes a hetero atom; and Y −  is an organic or inorganic anion. 
       
     
     
         11 . The method according to  claim 10 , wherein the nitrogen compound or the sulfur compound has a content of 0.1˜100 parts by weight based on 100 parts by weight of the metal salt. 
     
     
         12 . A metal nanostructure formed using the method of  claim 1 . 
     
     
         13 . The method according to  claim 5 , wherein the anion of the ionic liquid is any one selected from Br − , Cl − , I − , BF 4   − , PF 6   − , ClO 4   − , NO 3   − , AlCl 4   − , Al 2 Cl 7   − , AsF 6   − , SbF 6   − , CH 3 COO − , CF 3 COO − , CH 3 SO 3   − , C 2 H 5 SO 3   − , CH 3 SO 4   − , C 2 H 5 SO 4   − , CF 3 SO 3   − , (CF 3 SO 2 ) 2 N − , (CF 3 SO 2 ) 3 C − , (CF 3 CF 2 SO 2 ) 2 N − , C 4 F 9 SO 3   − , C 3 F 7 COO − , and (CF 3 SO 2 )(CF 3 CO)N − . 
     
     
         14 . The method according to  claim 3 , wherein, in addition to the ionic liquid, metal salt and reducing solvent, a nitrogen compound represented by Formula 2A below or a sulfur compound represented by Formula 2B below is used as an additive: 
       
         
           
           
               
               
           
         
         wherein R 5 , R 6 , R 7  and R 8  are identical to or different from each other, are each independently selected from hydrogen and a hydrocarbon group of C1-C20, and includes a hetero atom; and Y −  is an organic or inorganic anion, 
       
       
         
           
           
               
               
           
         
         wherein R is a monomolecular or polymeric hydrocarbon group, and includes a hetero atom; and Y −  is an organic or inorganic anion. 
       
     
     
         15 . The method according to  claim 4 , wherein, in addition to the ionic liquid, metal salt and reducing solvent, a nitrogen compound represented by Formula 2A below or a sulfur compound represented by Formula 2B below is used as an additive: 
       
         
           
           
               
               
           
         
         wherein R 5 , R 6 , R 7  and R 8  are identical to or different from each other, are each independently selected from hydrogen and a hydrocarbon group of C1-C20, and includes a hetero atom; and Y −  is an organic or inorganic anion, 
       
       
         
           
           
               
               
           
         
         wherein R is a monomolecular or polymeric hydrocarbon group, and includes a hetero atom; and Y −  is an organic or inorganic anion. 
       
     
     
         16 . The method according to  claim 5 , wherein, in addition to the ionic liquid, metal salt and reducing solvent, a nitrogen compound represented by Formula 2A below or a sulfur compound represented by Formula 2B below is used as an additive: 
       
         
           
           
               
               
           
         
         wherein R 5 , R 6 , R 7  and R 8  are identical to or different from each other, are each independently selected from hydrogen and a hydrocarbon group of C1-C20, and includes a hetero atom; and Y −  is an organic or inorganic anion, 
       
       
         
           
           
               
               
           
         
         wherein R is a monomolecular or polymeric hydrocarbon group, and includes a hetero atom; and Y −  is an organic or inorganic anion. 
       
     
     
         17 . The method according to  claim 6 , wherein, in addition to the ionic liquid, metal salt and reducing solvent, a nitrogen compound represented by Formula 2A below or a sulfur compound represented by Formula 2B below is used as an additive: 
       
         
           
           
               
               
           
         
         wherein R 5 , R 6 , R 7  and R 8  are identical to or different from each other, are each independently selected from hydrogen and a hydrocarbon group of C1-C20, and includes a hetero atom; and Y −  is an organic or inorganic anion, 
       
       
         
           
           
               
               
           
         
         wherein R is a monomolecular or polymeric hydrocarbon group, and includes a hetero atom; and Y −  is an organic or inorganic anion. 
       
     
     
         18 . The method according to  claim 7 , wherein, in addition to the ionic liquid, metal salt and reducing solvent, a nitrogen compound represented by Formula 2A below or a sulfur compound represented by Formula 2B below is used as an additive: 
       
         
           
           
               
               
           
         
         wherein R 5 , R 6 , R 7  and R 8  are identical to or different from each other, are each independently selected from hydrogen and a hydrocarbon group of C1-C20, and includes a hetero atom; and Y −  is an organic or inorganic anion, 
       
       
         
           
           
               
               
           
         
         wherein R is a monomolecular or polymeric hydrocarbon group, and includes a hetero atom; and Y −  is an organic or inorganic anion. 
       
     
     
         19 . The method according to  claim 8 , wherein, in addition to the ionic liquid, metal salt and reducing solvent, a nitrogen compound represented by Formula 2A below or a sulfur compound represented by Formula 2B below is used as an additive: 
       
         
           
           
               
               
           
         
         wherein R 5 , R 6 , R 7  and R 8  are identical to or different from each other, are each independently selected from hydrogen and a hydrocarbon group of C1-C20, and includes a hetero atom; and Y −  is an organic or inorganic anion, 
       
       
         
           
           
               
               
           
         
         wherein R is a monomolecular or polymeric hydrocarbon group, and includes a hetero atom; and Y −  is an organic or inorganic anion. 
       
     
     
         20 . The method according to  claim 13 , wherein, in addition to the ionic liquid, metal salt and reducing solvent, a nitrogen compound represented by Formula 2A below or a sulfur compound represented by Formula 2B below is used as an additive: 
       
         
           
           
               
               
           
         
         wherein R 5 , R 6 , R 7  and R 8  are identical to or different from each other, are each independently selected from hydrogen and a hydrocarbon group of C1-C20, and includes a hetero atom; and Y −  is an organic or inorganic anion, 
       
       
         
           
           
               
               
           
         
         wherein R is a monomolecular or polymeric hydrocarbon group, and includes a hetero atom; and Y −  is an organic or inorganic anion.