Method for producing a solid nanocomposite material based on hexa- and octa-cyanometallates of alkali metals

1. A method for producing a solid nanocomposite material comprising nanoparticles of a metal coordination polymer with CN ligands, said nanoparticles satisfying the formula [Alk + x ]M n+ [M′(CN) m ] z− wherein Alk is an alkali metal, x is 1 or 2, M is a transition metal, n is 2 or 3, M′ is a transition metal, m is 6 or 8, z is 3 or 4; said cations M n+ of the metal coordination polymer being bound through an organometallic or metal coordination bond to an organic group R2 of an organic graft, and said organic graft being further chemically attached to at least one surface of a solid support by reaction of a group R1 of said organic graft with said surface; said method comprising the following successive steps:

a) a solid support is provided;

b) the chemical attachment of the organic graft to the surface of the solid support is achieved;

c) the solid support to the surface of which is attached the organic graft is put into contact with a solution containing the M n+ ion and then the thereby grafted solid support obtained is washed one or several times and is optionally dried;

d) the grafted solid support obtained at the end of step c) is put into contact with a solution containing a complex or salt of [M′(CN) m ] z− and a salt of an alkali metal Alk, and then the thereby obtained solid support is washed once or several times, and is optionally dried; and

e) steps c) to d) are optionally repeated, wherein

f) if the steps c) and d) are the ultimate steps of the method, then during step c) the obtained grafted solid support is washed once or several times and is dried, and during step d), the thereby obtained solid support is washed one or several times and dried.

2. The method according to claim 1 , wherein M n+ is Fe 2+ , Ni 2+ , Fe 3+ , Co 2+ , Cu 2+ , or Zn 2+ .

3. The method according to claim 1 , wherein M′ is Fe 2+ or Fe 3+ or Co 3+ , and m is 6; or M′ is Mo 5+ , and m is 8.

4. The method according to claim 1 , wherein [M′(CN) m ] z− is [Fe(CN) 6 ] 3− , [Fe(CN) 6 ] 4− , [Co(CN) 6 ] 3− or [Mo(CN) 8 ] 3− .

5. The method according to claim 1 , wherein the cations M n+ are Ni 2+ , Cu 2+ , Fe 2+ or Fe 3+ cations and the anions are [Fe(CN) 6 ] 3− or [Fe(CN) 6 ] 4− anions.

6. The method according to claim 1 , wherein M n+ is Fe 3+ and [M′(CN) m ] z− is [Mo(CN) 8 ] 3− .

7. The method according to claim 1 , wherein M n+ is Co 2+ or Ni 2+ and [M′(CN) m ] z− is [Co(CN) 6 ] 3− .

8. The method according to claim 1 , wherein the nanoparticles fit the formula K[Cu II Fe III (CN) 6 ] or K 2 [Cu II Fe II (CN) 6 ].

9. The method according to claim 1 , wherein the nanoparticles have the shape of a sphere or a spheroid.

10. The method according to claim 1 , wherein the nanoparticles have a diameter from 3 nm to 30 nm.

11. The method according to claim 1 , wherein the organic group R2 is selected from the group consisting of nitrogen-containing groups; oxygen-containing groups; phosphorus-containing groups; and macrocyclic groups.

12. The method according to claim 1 , wherein the organic group R1 is selected from the group consisting of silane groups; carboxyl groups; carboxylated groups; phosphonate groups; phosphonic acid groups; alkenyl groups; alkynyl groups; and conjugate diene groups.

13. The method according to claim 1 , wherein the organic graft fits the formula R1-L-R2 wherein L is a linking group.

14. The method according to claim 13 , wherein the organic graft is (EtO) 2 —(P═O)—(CH 2 ) 2 —NH—(CH 2 ) 2 —NH 2 , or 2-aminoethyl-3-aminopropyl-trimethoxysilane.

15. The method according to claim 1 , wherein the support comprises a material selected from the group consisting of metal oxides and mixtures thereof; metalloid oxides and mixtures thereof; mixed metal and/or metalloid oxides; metal aluminosilicates; metal silicates and mixtures thereof; metal titanates, metalloid titanates, and mixtures thereof; metal carbides; metalloid carbides and mixtures thereof; mixtures of metal oxides and/or metalloid oxides; glasses; carbons; and composite materials comprising two materials or more from among the aforementioned materials.

16. The method according to claim 1 , wherein the support is in a form selected from the group consisting of particles; membranes; felts; and monoliths.

17. The method according to claim 16 , wherein the support is in the form of a powder consisting of particles and has a grain size from 0.5 mm to 1 mm.

18. The method according to claim 1 , wherein the support has a BET specific surface area from 50 to 500 m 2 /g.

19. The method according to claim 1 , wherein the chemical binding of the organic graft to the surface of the solid support is achieved by putting the solid support in contact with a solution of the organic graft, in a solvent selected from the group consisting of water, alcohols, and mixtures thereof.

20. The method according to claim 1 , wherein the solution containing the M n+ ion is a solution of one or several salts containing the M n+ ion in a solvent selected from the group consisting of water, alcohols and mixtures thereof.

21. The method according to claim 1 , wherein the solution containing a complex or salt of (M′(CN) m ) z− and a salt of an alkali metal Alk is a solution in a solvent selected from the group consisting of water, alcohols and mixtures thereof.

22. The method according to claim 1 , wherein the steps c) and d) are carried out in a static mode or batch mode, or in a dynamic mode.

23. The method according to claim 1 , wherein the steps c) and d) are repeated from 1 to 10 times.