Metal deposits, compositions, and methods for making the same

1. A method of forming a metal deposit on a substrate, the method comprising:

forming a metal deposit on a substrate from an electrolyte composition, the electrolyte composition comprising a carboxamide, a trialkylamine hydrochloride, and a metal salt;

the metal deposit being formed on the substrate by inducing a potential between the metal salt and the substrate through the electrolyte composition to cause a metal-metal bond to form between the metal salt and the substrate;

the carboxamide comprising Formula (I):

wherein n is 1 to 6;

each Q is O;

R 1 is independently chosen from H or alkyl, and R 3 is NR 4 R 5 ; or R 1 and R 3 are taken together to form a ring; and

each R 2 , R 4 , and R 5 is independently chosen from H or alkyl;

the trialkylamine hydrochloride being selected from the group consisting of trimethylamine hydrochloride (TMA-HCl), triethylamine hydrochloride (TEA-HCl), triethanolamine hydrochloride, and combinations thereof; and

the metal salt having a formula MX y , wherein M is a metal, X is a halide, and y is an oxidation number of M;

wherein the trialkylamine hydrochloride and the carboxamide are present in the electrolyte composition in molar ratio between 1:3 and 1:30 to form an ionic liquid, and the metal salt is present in the electrolyte composition in a concentration between 0.2 and 1.5 moles per liter of the ionic liquid; and

wherein the metal deposit is formed on the substrate from the electrolyte composition such that the metal deposit has an average grain size between 0.2 μm and 3 μm and contains less than 1 mol % of each oxygen, carbon, and chlorine.

2. The method of claim 1 , wherein the carboxamide of Formula (I) comprises a compound of Formula (II):

wherein n is 1 to 6;

R 1 , R 4 , and R 5 are independently chosen from H or alkyl; and

each R 2 is chosen from H or alkyl.

3. The method of claim 2 , wherein the carboxamide of Formula (II) comprises a compound of Formula (III):

wherein n is 1 to 6.

4. The method of claim 1 , wherein the carboxamide of Formula (I) comprises a compound of Formula (IV):

n is 2 to 6;

each Q is O; and

each R 2 , R 4 , and R 5 is independently chosen from H or alkyl.

5. The method of claim 4 , wherein the carboxamide of Formula (IV) comprises a compound of Formula (V):

each Q is O; and

each R 2 , R 4 , and R 5 is independently chosen from H or alkyl.

6. The method of claim 1 , wherein the carboxamide of Formula (I) is selected from the group consisting of urea, biuret, triuret, tetrauret, pentauret, hexauret, cyanuric acid, ammelide, ammeline, and combinations thereof.

7. The method of claim 6 , wherein the carboxamide is urea or biuret.

8. The method of claim 1 , wherein the trialkylamine hydrochloride and the carboxamide are in molar ratio of 1:5.

9. The method of claim 1 , wherein the trialkylamine hydrochloride and the carboxamide are in molar ratio of 1:10.

10. The method of claim 1 , wherein the concentration of metal salt is 0.3 moles per liter of the ionic liquid.

11. The method of claim 1 , wherein M is Fe.

12. The method of claim 1 , wherein X is Cl.

13. The method of claim 1 , wherein y is 3.

14. The method of claim 1 , wherein the metal deposit is an iron deposit.

15. The method of claim 1 , wherein M is Fe, X is Cl, and y is 3, and the metal deposit is an iron deposit.

16. The method of claim 1 , wherein the potential has a current density between 10 mA/cm 3 and 300 mA/cm 3 .

17. The method of claim 1 , wherein the potential has a reducing potential of between −0.6 V and −2.2 V.

18. The method of claim 1 , wherein the concentration of metal salt is 0.3 moles per liter of the ionic liquid.