Electrochemical mediated synthesis of silver nanoparticles in solution

Methyl viologen MV2+ and tetraviologen calix[4]resorcinol MVCA-C58+ with n-pentyl substituents in the resorcinol rings at potentials of MV2+/MV•+ and MVCA-C58+ /MVCA-C54•+ redox couples proved to be effective mediators of the electrochemical reduction of Ag+ ions in DMF/0.1 M Bu4NPF6. The potentiostatic nondiaphragm electrolysis at controlled mediator reduction potentials at room temperature using an Ag anode as an in situ supplier of Ag+ led to the formation of metallic silver nanoparticles in solution. The only resulting effect of electrolysis was the quantitative transfer of the metal anode into the metal nanoparticles in solution. In the case of MV2+, the nanoparticles aggregated into larger particles. MVCA-CC58+ serves not only as a mediator, but also, to some extent, as a stabilizer of silver nanoparticles and can be recorded by a set of experimental methods.