CORE-SHELL NANOWIRE ELECTRODES AND METHODS OF MAKING THE SAME
An aspect of the present disclosure is a method that includes depositing an ink as a liquid strand onto a substrate, transforming the liquid strand to a precursor strand, converting at least a portion of the precursor strand to a nanowire that includes a first metal, and coating the nanowire with a second metal to form a core-shell nanowire having a core and a shell, where at least a portion of the transforming occurs during the depositing, and the core includes the nanowire and the shell includes the second metal.
1 . A method comprising:
depositing a liquid strand comprising an ink onto a substrate;
transforming the liquid strand to a precursor strand;
converting at least a portion of the precursor strand to a nanowire comprising a first metal; and
coating the nanowire with a second metal to form a core-shell nanowire comprising a core and a shell, wherein:
at least a portion of the transforming occurs during the depositing, and
the core comprises the nanowire and the shell comprises the second metal.
2 . The method of claim 1 , wherein the first metal and the second metal are the same.
3 . The method of claim 1 , wherein the substrate comprises at least one of a metal oxide, a transparent conducting oxide (TCO), a glass, or a plastic.
4 . The method of claim 1 , wherein the first metal comprises at least one of silver, copper, gold, aluminum, nickel, platinum, palladium, zinc, or iron.
5 . The method of claim 4 , wherein the second metal comprises at least one of copper, silver, gold, aluminum, nickel, platinum, palladium, zinc, or iron.
6 . The method of claim 5 , wherein the first metal is different than the second metal.
7 . The method of claim 1 , wherein the ink comprises a metal precursor and a polymer.
8 . The method of claim 7 , wherein the ink is prepared by:
preparing a metal ink comprising the metal precursor;
preparing a solution comprising the polymer; and
combining the metal ink and the solution to form the ink.
9 . The method of claim 1 , wherein the depositing comprises electrospinning.
10 . The method of claim 1 , wherein the converting results in at least a portion of the first metal transferring to a surface of the precursor strand.
11 . The method of claim 1 , wherein the converting comprises exposing a surface of the precursor strand to at least one of ultraviolet light, ozone, or plasma.
12 . The method of claim 11 , wherein the converting comprises ultraviolet light and ozone.
13 . The method of claim 8 , wherein the converting comprises exposing a surface of the precursor strand to at least one of a liquid or a gas.
14 . The method of claim 13 , wherein:
the precursor strand is exposed to hydrogen gas, and
the hydrogen gas reduces the polymer and the silver salt.
15 . The method of claim 13 , wherein:
the precursor strand is exposed to an acid, and
the acid at least one of depolymerizes or decomposes the polymer.
16 . The method of claim 1 , wherein the converting further comprises heating at least one of the precursor strand or the nanowire.
17 . The method of claim 1 , wherein the coating comprises electroless plating of the second metal onto the nanowire.
18 . A device comprising:
a network of physically interconnected core-shell nanowires deposited on a substrate, wherein:
each nanowire comprises a core comprising a first metal and a shell comprising a second metal positioned around the core,
each core-shell nanowire has a diameter, Dnw, between 1 nm and 1 μm, and
the substrate comprises at least one of a metal oxide, a transparent conducting oxide (TCO), a glass, or a plastic.
19 . The device of claim 18 , wherein the network has a nanowire areal coverage on the substrate between 0.1% and 50%.
20 . The device of claim 18 , wherein the device is characterized by a Haacke Figure of Merit between 1×10 −3 ·Ω −1 and 700×10 −3 ·Ω −1 .