The present disclosure is drawn to methods and systems for producing solutions containing ultrafine metal particles. The method for producing ultrafine metal particles in an aqueous medium includes providing a reaction chamber having a transition metal anode and a transition metal cathode disposed therein. The reaction chamber can also contain an aqueous medium. An anode and cathode are associated at a distance with respect to one another such that when activated by a power source, a discharge arc occurs between the anode and cathode within the aqueous medium. Activation of a power source causes the discharge arc to occur between the anode and the cathode, thereby generating ultrafine metal particles suspended within the aqueous medium.