Process for near-infrared-driven decomposition of metal precursors for the formation of amorphous metal and metal oxide films
The present invention provides a method for making materials and electrocatalytic materials comprising amorphous metals or metal oxides. This method provides a scalable preparative approach for accessing state-of-the-art electrocatalyst films, as demonstrated herein for the electrolysis of water, and extends the scope of usable substrates to include those that are non-conducting and/or three-dimensional electrodes.
1. A process for forming an amorphous metal-containing electrocatalytic film, the process comprising the steps of:
a) providing a substrate, wherein the substrate is glass, fluorine-doped tin oxide-coated glass, perfluorinated polymer membrane, a synthetic polymer, a metallic substrate, plastic, glassy carbon or stainless steel;
b) coating the substrate with a metal precursor solution; and
c) exposing the coated substrate to near-infrared radiation to form the amorphous metal-containing film.
2. The process according to claim 1 , wherein the amorphous metal-containing film is an amorphous metal oxide, an amorphous mixed metal oxide, an amorphous metal, or an amorphous mixed metal.
3. The process according to claim 1 , wherein the amorphous metal-containing film comprises a metal selected from iron, iridium, manganese, nickel, copper, ruthenium, cobalt, tungsten, indium, tin, molybdenum, or any combination thereof.
4. The process according to claim 1 , wherein the metal precursor is a metal salt.
5. The process according to claim 4 , wherein the metal salt is MCl x or M(NO 3 ) x , where x is 2 or 3.
6. The process according to claim 4 , wherein the metal salt is selected from the group consisting of FeCI 3 , Fe(NO 3 ) 3 , IrCl 3 , NiCl 2 , Ni(NO 3 ) 2 , Fe 2 Ni 3 Cl, CoCl 2 , RuCl 3 , CuCl 2 , and WCl 6 .
7. The process according to claim 1 , wherein the metal precursor is a metal coordination complex.
8. The process according to claim 7 , wherein the metal coordination complex is a 2-ethylhexanoate derivative or an acetylacetonate derivative.
9. The process according to claim 7 , wherein the metal coordination complex is selected from the group consisting of Fe(eh)3, Cu(eh) 2 , lr(acac)3, Ni(eh) 2 , Mn(eh)3, Co(eh) 2 , Mo(eh)2, Sn(eh)2, In(acac)3, and Fe2Ni3(eh)3.
10. The process according to claim 1 , wherein the step of exposing the coated substrate to near-infrared radiation is conducted in an oxidizing atmosphere.
11. The process according to claim 10 , wherein the amorphous metal-containing film comprises α-FeO x , α-IrO x , α-NiO x , α-MnO x , -α-Fe 2 Ni 3 O x α-CuO x , α-CoO x , α-MoO x , α-SnO x , αInO x , α-RuO x , or α-WO x .
12. The process according to claim 1 , wherein the step of exposing the coated substrate to near-infrared radiation is conducted in an inert atmosphere.
13. The process according to claim 12 , wherein the amorphous metal-containing film comprises α-Fe, α-Cu, α-Fe 2 Ni 3 , α-Ni, or α-Mn.
14. The process according to claim 1 , further comprising the step of tuning the properties of the electrocatalytic film.
15. The process according to claim 14 , wherein the tuning step comprises annealing the metal oxide film.