Population of metal oxide nanosheets, preparation method thereof, and electrical conductor and electronic device including the same

Abstract

An electrical conductor includes a substrate; and a first conductive layer disposed on the substrate and including a plurality of metal oxide nanosheets, wherein adjacent metal oxide nanosheets of the plurality of metal oxide nanosheets contact to provide an electrically conductive path between the contacting metal oxide nanosheets, wherein the plurality of metal oxide nanosheets include an oxide of Re, V, Os, Ru, Ta, Ir, Nb, W, Ga, Mo, In, Cr, Rh, Mn, Co, Fe, or a combination thereof, and wherein the metal oxide nanosheets of the plurality of metal oxide nanosheets have an average lateral dimension of greater than or equal to about 1.1 micrometers. Also an electronic device including the electrical conductor, and a method of preparing the electrical conductor.

What is claimed is: 
     
         1 . A population of nanosheets comprising
 a plurality of metal oxide nanosheets,   wherein the plurality of metal oxide nanosheets comprise an oxide of Re, V, Os, Ru, Ta, Ir, Nb, W, Ga, Mo, In, Cr, Rh, Mn, Co, Fe, or a combination thereof, and   wherein an average lateral dimension of the plurality of metal oxide nanosheets is greater than or equal to about 1.1 micrometers.   
     
     
         2 . The population of nanosheets of  claim 1 , wherein the plurality of metal oxide nanosheets has an average lateral dimension of greater than or equal to about 1.5 micrometers, and an average thickness of less than or equal to about 5 nanometers. 
     
     
         3 . The population of nanosheets of  claim 1 , wherein the plurality of metal oxide nanosheets comprises RuO 2+x  wherein 0≤x≤0.5, MnO 2 , Mn 3 O 7 , Mn 1−x Co x O 2  wherein 0<x≤0.4, VO 2 , CoO 2 , FeO 2 , ReO 2 , IrO 2 , InO 2 , or a combination thereof. 
     
     
         4 . A method of preparing the population of the nanosheets according to  claim 1 , the method comprising
 heat-treating a mixture comprising a transition metal oxide comprising Re, V, Os, Ru, Ta, Ir, Nb, W, Ga, Mo, In, Cr, Rh, Mn, Co, Fe, or a combination thereof and an alkali metal compound at a temperature of about 750° C. to about 950° C. for about 18 hours or more to obtain a layered alkali metal-transition metal oxide;   pulverizing the layered alkali metal-transition metal oxide to obtain a powder of the layered alkali metal-transition metal oxide;   rinsing the powder of the layered alkali metal-transition metal oxide with water to obtain a powder of a layered alkali metal-transition metal oxide hydrate;   treating the powder of the layered alkali metal-transition metal oxide hydrate with an acidic solution to obtain a layered proton-exchanged transition metal oxide hydrate wherein at least a portion of an alkali metal is exchanged with a proton;   contacting the layered proton-exchanged transition metal oxide hydrate with a C1 to C16 alkyl ammonium salt compound to obtain a layered transition metal oxide intercalated with a C1 to C16 alkyl ammonium cation; and   mixing the layered transition metal oxide intercalated with the C1 to C16 alkyl ammonium cation with a solvent to obtain a population of transition metal oxide nanosheets.   
     
     
         5 . The method of  claim 4 , wherein the heat-treating is performed for about 24 hours or more. 
     
     
         6 . The method of  claim 4 , wherein the powder of the layered alkali metal-transition metal oxide hydrate has an average particle diameter of greater than or equal to about 100 micrometers. 
     
     
         7 . The population of nanosheets of  claim 1 , wherein an average thickness of the plurality of metal oxide nanosheets is less than or equal to about 5 nanometers. 
     
     
         8 . The population of nanosheets of  claim 1 , wherein the average lateral dimension of the plurality of metal oxide nanosheets is greater than or equal to about 1.8 micrometers. 
     
     
         9 . The population of nanosheets of  claim 1 , wherein the average lateral dimension of the plurality of metal oxide nanosheets is greater than or equal to about 2.3 micrometers. 
     
     
         10 . The population of nanosheets of  claim 1 , wherein the average lateral dimension of the plurality of metal oxide nanosheets is greater than or equal to about 3.5 micrometers. 
     
     
         11 . The population of nanosheets of  claim 1 , wherein the average lateral dimension of the plurality of metal oxide nanosheets is greater than or equal to about 7.0 micrometers. 
     
     
         12 . The population of nanosheets of  claim 1 , wherein the average lateral dimension of the plurality of metal oxide nanosheets is less than or equal to about 30 micrometers. 
     
     
         13 . The population of nanosheets of  claim 1 , wherein the plurality of metal oxide nanosheets comprise an oxide of Re, V, Os, Ru, Ir, W, Ga, Mo, In, Cr, Rh, Mn, Co, Fe, or a combination thereof. 
     
     
         14 . The population of nanosheets of  claim 1 , wherein the plurality of metal oxide nanosheets comprise at least two types of alkylammonium compounds. 
     
     
         15 . The population of nanosheets of  claim 14 , wherein the at least two types of alkylammonium compounds comprises at least one of tetramethylammonium compound and tetraethylammonium compound and at least one of a tetrapropylammonium compound, a benzylalkylammonium compound and a tetrabutylammonium compound. 
     
     
         16 . A composition comprising the population of nanosheets of  claim 1  and a solvent. 
     
     
         17 . The composition of  claim 16 , wherein the solvent comprises water and optionally an alcohol. 
     
     
         18 . The composition of  claim 16 , wherein the composition further comprises a dispersing agent. 
     
     
         19 . The population of nanosheets of  claim 1 , wherein the average lateral dimension of the plurality of metal oxide nanosheets is less than or equal to about 10.5 micrometers.