Method of producing a synthetic diamond

1. A method of producing a synthetic diamond, the method comprising:

(a) capturing carbon dioxide from an atmosphere;

(b) performing electrolysis of water to provide hydrogen;

(c-1) electrochemically reacting the carbon dioxide obtained from step (a) with water to produce methane; and

(d) using the hydrogen obtained from step (b) and the methane obtained from step (c-1) to produce the synthetic diamond by chemical vapour deposition (CVD); and

(e) reacting oxygen produced from the electrolysis of the water in step (b) with carbon emissions produced by the chemical vapour deposition in step (d) to produce carbon dioxide.

2. The method of claim 1 , wherein step (a) comprises capturing carbon dioxide using a nanotube gas separator.

3. The method of claim 1 , wherein step (a) comprises cooling air to liquefy carbon dioxide in the air.

4. The method of claim 3 , wherein cooling the air to liquefy carbon dioxide in the air comprises compressing the air and then expanding the air.

5. The method of claim 4 , wherein the steps of compressing the air and then expanding the air are repeated.

6. The method of claim 5 , wherein the steps are repeated three times.

7. The method of claim 1 , wherein step (a) comprises capturing carbon dioxide using an amine-containing sorbent-material.

8. The method of claim 7 , wherein capturing carbon dioxide using the amine-coated sorbent-material is conducted at a temperature below 25° C.

9. The method of claim 8 , wherein the captured carbon dioxide is subsequently released by heating the amine-containing sorbent material to a temperature above 25° C.

10. The method of claim 1 , wherein step (b) comprises performing the electrolysis of water using at least one polymer electrolyte membrane (PEM) cell.

11. The method of claim 10 , wherein the electrolysis is performed at a temperature below 150° C.

12. The method of claim 1 , wherein step (c-1) is conducted in the presence of a metal catalyst.

13. The method of claim 12 , wherein the metal catalyst is a nickel-based catalyst.

14. The method of claim 1 , wherein step (c-1) is conducted with a direct current.

15. The method of claim 1 , wherein the CVD is carried out at a pressure of between 0.5 kPa and 100 kPa.

16. The method of claim 15 , wherein the CVD is carried out at a pressure of substantially 40 kPa.

17. The method of claim 1 , wherein the CVD is carried out at a temperature between 700° C. and 1000° C.

18. The method of claim 17 , wherein the CVD is carried out at a temperature of substantially 950° C.

19. The method of claim 1 , wherein a ratio of hydrogen to methane used in step (d) is in a range of from 1:1 to 9:1.

20. The method of claim 19 , wherein the ratio of hydrogen to methane used in step (d) is about 5:1.

21. The method of claim 1 , wherein the CVD is carried out on a substrate comprising diamond.

22. The method of claim 1 , further comprising reacting the carbon dioxide obtained from step (e) with the hydrogen obtained from step (b) to produce methane.

23. The method of claim 1 , wherein the method further comprises using energy from at least one renewable source to perform at least one of the steps (a)-(d).

24. The method of claim 23 , wherein the method further comprises using energy from at least one renewable source to perform the electrolysis.

25. The method of claim 1 , wherein the water used in step (b) comprises rainwater.

26. The method of claim 1 , wherein the water used in step (c-1) comprises rainwater.

27. The method of claim 1 , wherein the method further comprises an additional step, after step (d), of annealing the synthetic diamond.

28. The method of claim 1 , wherein the method further comprises an additional step of at least one of cutting and polishing the diamond produced in step (d).