Nanoparticles and preparation method

A method of forming metal-containing nanoparticles or oxide thereof, the method comprising:

• a. providing one or more transition metal ions by providing one or more metal ion-containing compounds;
• b. dissolving the one or more metal ion-containing compounds in a solvent to form a solution phase comprising the one or more metal ion-containing compounds as a solute dissolved in the solvent, followed by drying the one or more metal ion-containing compounds that are dissolved in the solvent in order to recover a dried one or more metal ion-containing compounds;
• c. a heating step in which the dried one or more metal ion-containing compounds are subjected to a temperature of at least 300° C. to form metal-containing nanoparticles or oxide thereof;
• d. a cooling step comprising cooling the product of step c;
• e. optionally, a passivating step in which the product of step d is passivated;
• and/or
• f. optionally, a step of acid leaching the product of step d, or, if step e is performed, a step of acid leaching the product of step e;
• wherein the one or more metal ion-containing compounds are transition metal complexes having ligands coordinated to a transition metal ion, the ligands being selected from the group consisting of glyoxime;
• a glyoxime derivative;
• salicylaldimine;
• and a salicylaldimine derivative.