METHOD FOR PRODUCING METAL AND/OR METALLOID COMPOUNDS IN AN IONIC LIQUID

Abstract

The disclosure provides a method of producing a metal compound. The method comprises contacting a metal source with a reaction mixture, wherein the reaction mixture comprises an ionic liquid and an oxidising agent, and thereby producing the metal compound.

Claims

1. A method of producing a metal and/or metalloid compound, the method comprising contacting a metal and/or metalloid source with a reaction mixture, wherein the reaction mixture comprises an ionic liquid and an oxidising agent, and thereby producing the metal and/or metalloid compound.

2. The method of claim 1, wherein the metal and/or metalloid source comprises or consists of a pure metal, a pure metalloid, an impure metal, an impure metalloid, an alloy, a metal containing compound or a metalloid containing compound, optionally wherein the metal and/or metalloid source comprises a metal or an alloy.

3. (canceled)

4. The method of claim 1, wherein the metal and/or metalloid source comprises or consists of aluminium, antimony, arsenic, astatine, barium, beryllium, bismuth, boron, cadmium, caesium, calcium, cerium, chromium, cobalt, copper, dysprosium, erbium, europium, gadolinium, gallium, germanium, gold, hafnium, holmium, indium, iridium, iron, lanthanum, lead, lithium, lutetium, magnesium, manganese, mercury, molybdenum, neodymium, nickel, niobium, osmium, palladium, platinum, polonium, potassium, praseodymium, rhenium, rhodium, rubidium, ruthenium, samarium, scandium, selenium, silicon, silver, sodium, tantalum, tellurium, terbium, thorium, thulium, tin, titanium, tungsten, uranium, vanadium, ytterbium, yttrium, zinc and/or zirconium.

5. The method of claim 1, wherein the metal and/or metalloid compound comprises oxygen, nitrogen, phosphorous, a halogen, sulphur, selenium, carbon and/or hydrogen, optionally wherein the metal and/or metalloid compound comprises an oxide group (O) or a hydroxide group (OH).

6. (canceled)

7. The method of claim 1, wherein the oxidising agent comprises or consists of water, hydrogen peroxide, ozone, oxygen, a halogen (e.g. fluorine, chlorine, iodine or bromine), potassium nitrate and/or a mineral acid, optionally wherein the oxidising agent is water.

8. (canceled)

9. The method of claim 1, wherein hydrogen gas is produced by the method as a co-product, and the method further comprises collecting the hydrogen gas.

10. The method of claim 1, wherein the ionic liquid consists of a cation and an anion and has a melting point or less than 350° C., optionally wherein the cation is an optionally substituted positively charged 3 to 15 membered heterocyclic ring or an optionally substituted positively charged 5 to 15 membered heteroaromatic ring.

11. (canceled)

12. The method of claim 10, wherein the cation is: ##STR00011## ##STR00012## ##STR00013## ##STR00014## wherein R.sup.1 to R.sup.14 are independently H, an optionally substituted C.sub.1-24 alkyl, an optionally substituted C.sub.2-24 alkenyl, an optionally substituted C.sub.2-24 alkynyl, an optionally substituted C.sub.3-24 cycloalkyl, an optionally substituted C.sub.6-12 aryl, —OR.sup.15, —SR.sup.15, —CN, —NR.sup.15R.sup.16, —SO.sub.3R.sup.15, —OSO.sub.3R.sup.15, —COR.sup.15, —COOR.sup.15, —NO.sub.2, —Cl, —Br, —F, or —I, or two of R.sup.1 to R.sup.14, together with the atoms to which they are attached, form an optionally substituted 3 to 15 membered ring, wherein R.sup.15 and R.sup.16 are independently H, an optionally substituted C.sub.1-24 alkyl, an optionally substituted C.sub.2-24 alkenyl, an optionally substituted C.sub.2-24 alkynyl, an optionally substituted C.sub.3-6 cycloalkyl or an optionally substituted C.sub.6-12 aryl.

13. The method of claim 10, wherein the cation is: ##STR00015## wherein R.sup.1 to R.sup.6 are independently H, an optionally substituted C.sub.1-24 alkyl, an optionally substituted C.sub.2-24 alkenyl, an optionally substituted C.sub.2-24 alkynyl, an optionally substituted C.sub.3-6 cycloalkyl, an optionally substituted C.sub.6-12 aryl, —OR.sup.15, —SR.sup.15, —CN, —NR.sup.15R.sup.16, —SO.sub.3R.sup.15, —OSO.sub.3R.sup.15, —COR.sup.15, —COOR.sup.15, —NO.sub.2, —Cl, —Br, —F or —I, or two of R.sup.1 to R.sup.6, together with the atoms to which they are attached, form an optionally substituted 3 to 15 membered ring wherein R.sup.15 and R.sup.16 are independently H, an optionally substituted C.sub.1-24 alkyl, an optionally substituted C.sub.2-24 alkenyl, an optionally substituted C.sub.2-24 alkynyl, an optionally substituted C.sub.3-6 cycloalkyl or an optionally substituted C.sub.6-12 aryl.

14. The method of claim 10, wherein the anion is F.sup.−, Cl.sup.−, Br.sup.−, I.sup.−, ClO.sub.4.sup.−, ##STR00016## BrO.sub.4.sup.−, NO.sub.3.sup.−, NC.sup.−, NCS.sup.−, NCSe.sup.−, ##STR00017## or a negatively charged metal complex, wherein R.sup.17 to R.sup.22 are independently H, an optionally substituted C.sub.1-24 alkyl, an optionally substituted C.sub.2-24 alkenyl, an optionally substituted C.sub.2-24 alkynyl, an optionally substituted C.sub.3-6 cycloalkyl, an optionally substituted C.sub.6-12 aryl, —OR.sup.15, —SR.sup.15, —CN, —NR.sup.15R.sup.16, —SO.sub.3R.sup.15, —OSO.sub.3R.sup.15, —COR.sup.15, —COOR.sup.15, —NO.sub.2, —Cl, —Br, —F or —I, or two of R.sup.17 to R.sup.22, together with the atoms to which they are attached, form an optionally substituted 3 to 15 membered ring, wherein R.sup.15 and R.sup.16 are independently H, an optionally substituted C.sub.1-24 alkyl, an optionally substituted C.sub.2-24 alkenyl, an optionally substituted C.sub.2-24 alkynyl, an optionally substituted C.sub.3-6 cycloalkyl or an optionally substituted C.sub.6-12 aryl.

15. The method of claim 10, wherein the inorganic liquid is 1-n-butyl-3-methylimidazolium chloride, butyl-dimethylammonium hydrogen sulphate, 1-n-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or methylimidazolium chloride.

16. The method according to claim 1, wherein the reaction mixture comprises or consist of the ionic liquid and the oxidizing agent in a weight ratio of between 1:1,000 and 1,000:1, between 1:750 and 750:1, between 1:500 and 500:1, between 1:250 and 250:1, between 1:100 and 100:1, between 1:50 and 50:1, between 1:25 and 25:1, between 1:15 and 15:1, between 1:10 and 10:1, between 1:7 and 7:1 or between 1:6 and 5:1.

17. The method according to claim 1, wherein the reaction mixture comprises or consists of the ionic liquid and the oxidizing agent in a molar ratio of between 1:1,000 and 100:1, between 1:500 and 50:1, between 1:250 and 10:1, between 1:100 and 5:1, between 1:80 and 3:1, between 1:70 and 21, between 1:60 and 1:1 or between 1:50 and 1:2.

18. The method according to claim 1, wherein the metal and/or metalloid source and the reaction mixture are contacted at a temperature between −50° C. and 500° C., between −25° C. and 400° C., between 0° C. and 300° C., between 5° C. and 200° C. or between 10° C. and 175° C.

19. The method according to claim 1, wherein the metal and/or metalloid source and the reaction mixture are contacted for at least 1 minute, at least 15 minutes, at least 30 minutes, at least 1 hour, at least 6 hours, at least 12 hours, at least 24 hours or at least 48 hours.

20. The method according to claim 1, wherein the method comprises separating the metal and/or metalloid compound from the ionic liquid, optionally wherein the method comprises purifying the ionic liquid after separation.

21. (canceled)

22. The method according to claim 1, wherein the method comprises heating the metal and/or metalloid compound to cause the metal and/or metalloid compound to chemically react and provide a further metal and/or metalloid compound, optionally wherein the further metal and/or metalloid compound is a metal oxide or a metalloid oxide.

23. (canceled)

24. A cupro-zinc-oxo-chloride complex.

25. The complex according to claim 24, wherein the complex comprises: between 1 and 75 at. % copper, between 0.1 and 20 at. % zinc, between 5 and 90 at. % oxygen, and between 0.1 and 30 at. % chlorine.

26. The complex according to claim 24, wherein the complex has an energy dispersive x-ray (EDX) spectrum substantially as shown in FIG. 13.

Description

DESCRIPTION OF DRAWINGS

[0089] For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:—

[0090] FIG. 1 is a scanning electron microscope (SEM) image of a zinc substrate exposed to 1-butyl-3-methylimidazolium chloride (XH.sub.2O=0.98 solution at 70±1° C.), showing ZnO nanorods after 4 d exposure (average size 90±40 nm);

[0091] FIG. 2 is an SEM image of a zinc substrate after exposure to 1-butyl-3-methylimidazolium chloride (XH.sub.2O=0.75 solution, 20±1° C.) for 26 d, showing the top of hexagonal nanorods (average size 150±30 nm);

[0092] FIG. 3 is an SEM image of zinc substrate after exposure to 1-butyl-3-methylimidazolium chloride (XH.sub.2O=0.75 solution, 20±1° C.) for 15 d, showing zinc chloride hydroxide monohydrate (Zn5(OH).sub.8Cl.sub.2.Math.H.sub.2O) crystal plates. Estimated thickness 2.5±1.5 m and diameter 19±8 μm;

[0093] FIG. 4 is an SEM image showing zinc substrate exposed to 1-butyl-3-methylimidazolium chloride (XH.sub.2O=0.98 solution at 20±1° C.) showing multiple Zn(OH).sub.2 octahedrons after 44 d exposure with a mean length of 21±6 μm;

[0094] FIGS. 5A and B are SEM images of ε-Zn(OH).sub.2 octahedrons and Zn.sub.5(OH).sub.8Cl.sub.2.Math.H.sub.2O (ZHC) particles, respectively, before calcination; FIG. 5C is an x-ray diffraction (XRD) spectra of the mixture Zn(OH).sub.2 and ZHC powder, showing signals from both compounds, main peaks form diffraction patterns have been labelled: (x) ZHC and (+) ε-Zn(OH).sub.2; FIGS. 5D and 5E are SEM images of ε-Zn(OH).sub.2 octahedrons and ZHC particles, respectively, after calcination; and FIG. 5F is an XRD spectra of the calcinated samples showing only signals from ZnO, main peaks have been abelled (.Math.) ZnO;

[0095] FIG. 6 is a summary of the most represented structures obtained when a zinc substrate was exposure to a 1-butyl-3-methylimidazolium chloride solution;

[0096] FIG. 7 is an SEM image of a brass substrate after exposure to 1-butyl-3-methylimidazolium chloride (XH.sub.2O=0.98 solution, 20±1° C.) for 18 d, showing the top of hexagonal nanorods (average size to ±0.2 μM);

[0097] FIG. 8 is an SEM image of an iron substrate after exposure to 1-butyl-3-methylimidazolium chloride (XH.sub.2O=0.98 solution, 70±1° C.) for 8 d, showing the formation of 500±100 nm Fe.sub.2O.sub.3 cubes and 4±1 μm cuboctahedra structures;

[0098] FIG. 9 is an SEM image of an iron substrate after exposure to 1-butyl-3-methylimidazolium chloride (XH.sub.2O=0.98 solution, 70±1° C.) for 3.5 d, showing the formation of 115±5 nm diameter hexagonal Iron oxide plates;

[0099] FIG. 10 is an SEM image of a copper substrate after exposure to 1-butyl-3-methylimidazolium chloride (XH.sub.2O=0.98 solution, 70±1° C.) for 15 d, showing the formation of dicopper chloride trihydroxide Cu.sub.2(OH).sub.3Cl crystals with an average edge size of 1.7±0.5 μm;

[0100] FIG. 11 is an SEM image of a zinc substrate after exposure to 1-butyl-3-methylimidazolium chloride (water content 60 wt %, 40±1° C., pH=3, mass ratio 1:1 stirring rate 250 rpm) for 7 d showing the formation of ZnO nanorods with an average length of 900±100 nm;

[0101] FIG. 12 is an SEM image of a brass substrate after exposure to 1-butyl-3-methylimidazolium chloride (water content 98 mol %, room temperature) for 18 d showing the formation of a cupro-zinc-oxo-chloride complex acicular crystals radiating from a core; and

[0102] FIG. 13 is an energy dispersive x-ray (EDX) spectrum of the cupro-zinc-oxo-chloride complex of FIG. 12.

EXAMPLES

Example 1—Synthesis of 90 nm Diameter Hexagonal Zinc Oxide (ZnO) Nanorods on Zinc Substrate by Direct Oxidation of Zn in 1-butyl-3-methylimidazolium Chloride

[0103] A disk of zinc (purity >99.95%, d=18 mm and 0.125 mm thickness) with a single 0.8 mm diameter hole was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in a 1-butyl-3-methylimidazolium chloride solution with a water content of 98 mol % (82 wt %), pre-heated to 70° C., with the help of a fluorocarbon filament. The metallic surface area to liquid volume ratio was 0.2 mL mm.sup.−2. The container with the solution and the suspended metal substrate was placed in a convection oven at 70° C. for 4 days. At the conclusion of the experiment, the substrate was removed from the solvent and quenched in demineralized water, then washed, with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of hexagonal zinc oxide (flat-top) of average size 90±40 nm as depicted in FIG. 1.

Example 2—Synthesis of 150 nm Diameter Hexagonal Zinc Oxide Nanorods on Zinc Substrate by Direct Oxidation of Zn in 1-butyl-3-methylimidazolium Chloride

[0104] A disk of zinc (purity >99.95%, d=18 mm and 0.125 mm thickness) with a single 0.8 mm diameter hole was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in a 1-butyl-3-methylimidazolium chloride solution with a water content of 75 mol %, pre-heated to 70° C., with the help of a fluorocarbon filament. The metallic surface area to liquid volume ratio was 0.2 mL mm.sup.−2. The container with the solution and the suspended metal substrate was placed in a convection oven at 20° C. for 26 days. At the conclusion of the experiment, the substrate was removed from the solvent and quenched in demineralized water, then washed, with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of hexagonal zinc oxide (flat-top) of average size 150±30 nm as depicted in FIG. 2.

Example 3—Synthesis of Zinc Chloride Hydroxide Monohydrate (Zn.SUB.5.(OH).SUB.8.Cl.SUB.2..Math.H.SUB.2.O Plates by Direct Oxidation of Zn in 1-butyl-3-methylimidazolium Chloride

[0105] A disk of zinc (purity >99.95%, d=18 mm and 0.125 mm thickness) with a single 0.8 mm diameter hole was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in a 1-butyl-3-methylimidazolium chloride solution with a water content of 98 mol %, pre-heated to 70° C., with the help of a fluorocarbon filament. The metallic surface area to liquid volume ratio was 0.2 mL mm.sup.−2. The container with the solution and the suspended metal substrate was placed in a convection oven at 70° C. for 15 days. At the conclusion of the experiment, the substrate was removed from the solvent and quenched in demineralized water, then washed, with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of various structures, such as zinc chloride hydroxide monohydrate (Zn.sub.5(OH).sub.8Cl.sub.2.Math.H.sub.2O) plate-like crystals of with an average thickness of 2.5 μm and average size of 19 μm as depicted in FIG. 3.

Example 4—Synthesis of Zinc Hydroxide (Zn(OH).SUB.2.) Octahedrons by Direct Oxidation of Zn in 1-butyl-3-methylimidazolium Chloride Solutions

[0106] A disk of zinc (purity >99.95%, d=18 mm and 0.125 mm thickness) with a single 0.8 mm diameter hole was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in a 1-butyl-3-methylimidazolium chloride solution with a water content of 98 mol %, at room temperature, with the help of a fluorocarbon filament, for 44 d. The metallic surface area to liquid volume ratio was 0.2 mL mm.sup.−2. At the conclusion of the experiment, the substrate was removed from the solvent and washed with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of various structures, such as zinc hydroxide (Zn(OH).sub.2) octahedrons crystals of with an average edge size of 21±6 μm as depicted in FIG. 4.

Example 5—Synthesis of ZnO Structures Through Calcination of Zinc Chloride Hydroxide Monohydrate (Zn.SUB.5.(OH).SUB.8.Cl.SUB.2..Math.H.SUB.2.O) Plate-Like Crystals and Zinc Hydroxide (Zn(OH).SUB.2.) Octahedrons Though Calcination of Samples Obtained by Direction Oxidation of Zinc in 1-butyl-3-methylimidazolium Chloride Solutions

[0107] Structures prepared in Examples 4 (Zn(OH).sub.2 octahedrons along with (Zn.sub.5(OH).sub.8Cl.sub.2.Math.H.sub.2O) plate-like crystals similar to the ones shown in Example 3) were removed mechanically from the substrate, by scratching the surface, and recovered. The collected powder containing both species was heated in a TGA instrument from ambient temperature to 650° C. at a rate of 5° C./min. The calcination process ended at 550° C. The post-calcination products contained only ZnO, and generally conserved the overall crystal shape of the initial compounds, with an increased porosity. For example, the Zn(OH).sub.2 octahedrons were converted to ZnO octahedrons and the (Zn.sub.5(OH).sub.8Cl.sub.2.Math.H.sub.2O) plate-like crystals were converted to ZnO plate-like crystals, as depicted in FIG. 5.

Example 6—Comparison of Different Conditions

[0108] The inventors compared the structures obtained using different reaction conditions, and their findings are provided in Table 1, below. The structures are illustrated in FIG. 6.

TABLE-US-00001 TABLE 1 Summary of the must representative structures obtained when a zinc disk is contacted with 1-butyl-3-methylimidazolium chloride solutions Water IL Content/mol % Temp/º C. Exposure Time [A] [B] [C] [D] [E] [G] [F] [H] [I] 2 75 120 5.8 days X X 1 75 20 18/26 days X 2 75 120 1 day X 2 75 120 16 hours X X X 2 98 20 6 days X 2 98 20 16 days X 1 98 20 18 days X 1 98 20 44 days X X X X 2 98 20 48 days X 1 98 70 3.5 days X X X X 1 98 70 15 days X X X X X X 2 98 120 1 day X X X 2 98 120 16 hours X

[0109] The IL for all experiments was 1-butyl-3-methylimidazolium chloride. IL-1 is from Sigma-Aldrich, with a purity of >98%, and IL-2 is from Iolitec, with a purity of >99%.

[0110] As shown in FIG. 6, [A] is ZnO flat-topped hexagonal rods, [B] is ε-Zn(OH).sub.2 octahedrons, [C] is ZHC plates, [D] is ZnO short rods (round and sharp ended), [E] is ZnO needles, [F] flat-topped hexagonal nano-rods, [G] is ZnO thick crystals, [H] is ZnO 3D needle flower, and [I] is ZnO 3D thick crystal flower.

Example 7—Synthesis of 1 μm Diameter Hexagonal Zinc Oxide (ZnO) Nanorods by Direct Oxidation of Brass in 1-butyl-3-methylimidazolium Chloride

[0111] A disk of brass (Cu 63% and Zn 37%, d=18 mm and 0.125 mm thickness) with a single 0.8 mm diameter hole was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in a 1-butyl-3-methylimidazolium chloride solution with a water content of 98 mol %, at room temperature, with the help of a fluorocarbon filament, for 18 d. The metallic surface area to liquid volume ratio was 0.2 mL mm.sup.−2. At the conclusion of the experiment, the substrate was removed from the solvent and washed with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of various structures, such as zinc hydroxide ZnO hexagonal rods crystals of with an average size of 1.0±0.2 μm as depicted in FIG. 7.

Example 8—Synthesis of 500 nm Cubes and 4 μm Cuboctahedra Iron Oxide by Direct Oxidation of Iron in 1-butyl-3-methylimidazolium Chloride

[0112] A disk of iron (purity 99.99%, d=18 mm and 0.125 mm thickness) with a single 0.8 mm diameter hole was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in a 1-butyl-3-methylimidazolium chloride solution with a water content of 98 mol %, pre-heated to 70° C., with the help of a fluorocarbon filament. The metallic surface area to liquid volume ratio was 0.2 mL mm.sup.−2. The container with the solution and the suspended metal substrate was placed in a convection oven at 70° C. for 8 days. At the conclusion of the experiment, the substrate was removed from the solvent and quenched in demineralized water, then washed, with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of 500±100 nm Fe.sub.2O.sub.3 cubes and 4±1 μm cuboctahedra structures as depicted in FIG. 8.

Example 9—Synthesis of 115 nm Diameter Hexagonal Iron Oxide Plate by Direct Oxidation of Iron in 1-butyl-3-methylimidazolium Chloride

[0113] A disk of iron (purity 99.99%, d=18 mm and 0.125 mm thickness) with a single 0.8 mm diameter hole was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in a 1-butyl-3-methylimidazolium chloride solution with a water content of 98 mol %, pre-heated to 70° C., with the help of a fluorocarbon filament. The metallic surface area to liquid volume ratio was 0.2 mL mm.sup.−2. The container with the solution and the suspended metal substrate was placed in a convection over at 70° C. for 3.5 days. At the conclusion of the experiment, the substrate was removed from the solvent and quenched in demineralized water, then washed, with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of 115±5 nm diameter hexagonal Iron oxide plates as depicted in FIG. 9.

Example 10—Synthesis of Dicopper Chloride Trihydroxide (Cu.SUB.2.(OH).SUB.3.C.SUB.1.) by Direct Oxidation of Copper in 1-butyl-3-methylimidazolium Chloride

[0114] A disk of copper (purity >99.9%, d=18 mm and 0.125 mm thickness) with a single 0.8 mm diameter hole was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in a 1-butyl-3-methylimidazolium chloride solution with a water content of 98 mol %, pre-heated to 70° C., with the help of a fluorocarbon filament. The metallic surface area to liquid volume ratio was 0.2 mL mm.sup.−2. The container with the solution and the suspended metal substrate was placed in a convection over at 70° C. for 15 days. At the conclusion of the experiment, the substrate was removed from the solvent and quenched in demineralized water, then washed, with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of bi-pyramidal dicopper chloride trihydroxide Cu.sub.2(OH).sub.3Cl crystals with an average edge size of 1.7±0.5 μm as depicted in FIG. 10.

Example 11—Synthesis of Zinc Oxide (ZnO) Nanorods by Direct Oxidation of Zinc Granules in 1-butyl-3-methylimidazolium Chloride

[0115] The synthesis of zinc oxide nanoparticles was carried out via the oxidation zinc granules (20-30 mesh) in a solution of an aqueous 1-butyl-3-methylimidazolium chloride with a water content of 94 mol % (60 wt %). Upon adjusting the pH, concentrated HCl was added dropwise into deionized water (100 mL) until a pH of 3 was achieved. Subsequently, 1-butyl-3-methylimidazolium chloride was added until concentrations of 60 wt % water was achieved. The 1-butyl-3-methylimidazolium chloride solutions were added to the zinc granules in desiccation tubes in a 1:1 mass ratio. Stirring rate was 250 rpm rotation speeds in an incubator (New Brunswick Scientific, Innova 42 Incubator Shaker Series) and the synthesis carried out over a period of 7 days at 40° C. At the end of the experiment, the zinc oxide product was placed into centrifuge tubes (falcon, 50 mL) and washed using two aliquots of water and one of absolute ethanol, centrifuging for 40 minutes between each washing in order to effectively separate the product from the solution. The ionic liquid was recovered via rotary evaporation. After washing the product was calcinated in a vacuum oven overnight at 150° C. This procedure yielded ZnO nanorods of an average length of 700±200 nm as depicted in Figure ii.

Example 12—Synthesis of Nickel Based Compounds by Direct Oxidation of Nickel in Butyl-Dimethylammonium Hydrogen Sulphate

[0116] A disk of nickel (purity >99.98%, d=18 mm and 0.125 mm thickness) was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in 3 ml butyl-dimethylammonium hydrogen sulphate solution with a water content of 75 mol % (24 wt %), pre-heated to 150° C. The container with the solution and the suspended metal substrate was placed in a convection oven at 150° C. for 48h. At the conclusion of the experiment, the substrate was removed from the solvent and quenched in demineralized water, then washed, with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of a green solid on the surface of the substrate.

Example 13—Synthesis of Aluminium Based Compounds by Direct Oxidation of Nickel in Butyl-Dimethylammonium Hydrogen Sulphate

[0117] A disk of aluminium (purity >99.999%, d=18 mm and 0.125 mm thickness) was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in 3 ml butyl-dimethylammonium hydrogen sulphate solution with a water content of 75 mol %, pre-heated to 150° C. The container with the solution and the suspended metal substrate was placed in a convection oven at 150° C. for 48h. At the conclusion of the experiment, the substrate was converted into a white solid.

[0118] It is noted that this method generates hydrogen gas as a co-product. Without wishing to be bound by theory, the inventors note that there are several reactions that can take place:

2Al+6H.sub.2O.fwdarw.2Al(OH).sub.3+3H.sub.2

2Al(OH).sub.3.fwdarw.Al.sub.2O.sub.3+3H.sub.2

Al+2H.sub.2O.fwdarw.AlOOH+1.5H.sub.2

[0119] The inventors note that the hydrogen gas could be captured.

Example 14—Synthesis of Titanium Based Compounds by Direct Oxidation of Nickel in Butyl-Dimethylammonium Hydrogen Sulphate

[0120] A washer of titanium (Grade 2, d=18 mm and 0.125 mm thickness) was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in 3 ml butyl-dimethylammonium hydrogen sulphate solution with a water content of 75 mol %, pre-heated to 150° C. The container with the solution and the suspended metal substrate was placed in a convection oven at 150° C. for 48h. At the conclusion of the experiment, the substrate was removed from the solvent and quenched in demineralized water, then washed, with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of a white solid precipitate in the solution.

Example 15—Synthesis of Copper(II) Bis(Trifluoromethanesulfonyl)Imide by Direct Oxidation of Copper in 1-Butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide

[0121] A disk of copper (purity 99.9%, d=18 mm and 0.125 mm thickness) with a single 0.8 mm diameter hole was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide at room temperature, with the help of a fluorocarbon filament. The metallic surface area to liquid volume ratio was 0.2 mL mm.sup.−2. The container with the ionic liquid and the suspended metal substrate was placed in a vacuum oven at 150° C. for 68 days. At the conclusion of the experiment, the substrate was removed from the solvent and quenched in demineralized water, then washed, with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of a green solid over the surface of the substrate.

Example 16—Synthesis of a Cupro-Zinc-Oxo-Chloride Complex by Direct Oxidation of Brass in 1-butyl-3-methylimidazolium Chloride

[0122] A disk of brass (Cu 63% and Zn 37%, d=18 mm and 0.125 mm thickness) with a single 0.8 mm diameter hole was used. The metal substrate was prepared at room temperature by washing with demineralized water, industrial methylated spirits, and acetone. After which, the sample was dried for 45 min at 105° C. and then cooled in a desiccator for 30 min. The metal substrate was immersed in a 1-butyl-3-methylimidazolium chloride solution with a water content of 98 mol % at room temperature, with the help of a fluorocarbon filament, for 18 days. The metallic surface area to liquid volume ratio was 0.2 mL mm.sup.−2. At the conclusion of the experiment, the substrate was removed from the solvent and quenched in demineralized water, then washed, with demineralized water, industrial methylated spirits, and acetone. This yielded to the formation of cupro-zinc-oxo-chloride complex acicular crystals radiating from a core as depicted in FIG. 12. The EDX spectrum is shown in FIG. 13, and the complex was determined to have a Cu:Zn:O:Cl atomic ratio of 11:1:25.1:2.

CONCLUSION

[0123] The inventors have demonstrated an Oxidative Ionothermal Synthesis (OIS) of nano/micro materials (both crystalline and amorphous) by direct oxidation of metals in an IL and water mixture. By adjusting the water content, temperature and exposure time, different species such can be obtained.

[0124] The use of a mixture comprising an IL and an oxidising agent for making nanoparticles via direct oxidation of metals (OIS) might be used to synthetize materials-by-design (as hetero-structures, core-shell structures or metals with modified surfaces) with physicochemical properties tailored to meet industrial relevant needs. Additionally, the use of these solvents in combination with metals/metalloids could lead to a more cost-effective and environmentally friendly processes for large-scale synthesize synthesis of a wide range of nano and micro materials.

[0125] While not being bound to a particular theory, it is believed that, during the course of the reactions discussed herein, the metal/metalloid precursor is first oxidised by the oxidizing agent and then partially solubilised in the polar regions of the ionic liquid, which can stabilize the metal/metalloid ions. The concentration of metal/metalloid in these environments increases until it reaches a critical concentration, which leads to nucleation of metal/metalloid compounds. These compounds undergo further growth, and by kinetic and/or thermodynamic control, are formed into microparticles or nanoparticles. The particles can grow as individual particles in the solution or attached to the precursor surface, to form a film or composite material. The ionic liquid may be selected to provide a solvent environment that is specifically designed for particular precursors and oxidising agents. Accordingly, it appears that microparticles or nanoparticles of any given composition and morphology can be produced by the synthetic pathways described herein.