Introduction

The invention is based on the use of a non-toxic reducing agent, at no cost and easy to obtain, to produce metal nanoparticles (eg. Zerovalent iron nZVI), in full compliance with the principles of “green chemistry” and “circular economy” , ranging in size from 30 to 50 nm.

Technical features

The synthesis process involves the use of a metal precursor, a basic solution for pH correction and a natural extract from the waste of the olive oil industry, obtained by extracting the reducing compounds from solid waste (pomace, residual pulp, leaves) or liquids (water for washing olives, water for washing oil, vegetation water, brines) using the wastewater from the industrial process as an extraction medium. In a typical synthesis procedure, it is necessary to prepare an aqueous solution of a salt of the metal precursor and an aqueous solution of a base. The precursor solution is initially placed in a batch or continuous reactor with mechanical stirring, under micro-mixing conditions. Micro-mixing homogenizes the reactant species and allows chemical reactions on a molecular scale. It is necessary to add the right amount of extract, previously prepared, for the synthesis. Immediately thereafter it is necessary to increase the pH of the medium for the chemical reduction process of the metal precursor to take place.

Possible Applications

• As catalysts in the process industry, in fine chemicals, in pharmaceuticals;
• As a “drug carrier” in the field of anticancer medicine or in the biomedical field;
• In environmental catalysis processes;
• As composite filling materials;
• In the field of electronics or optics;
• In the agro-food industry.

Advantages

• Economically and environmentally sustainable process.
• No use of inert gases in solution during synthesis, as the nanoparticles produced are protected by the polyphenolic matrix;
• Use of normal and easily available equipment;
• Do not use high pressures or temperatures, nor corrosive or chemically aggressive reagents.