Benzimidazo[1',2':1,2]Quinolino[4,3-b][1,2,5]Oxodiazolo[3,4-f]Quinoxaline—New Mediator for Electrosynthesizing Metal Nanoparticles

Abstract

Spherical silver nanoparticles (NP-Ag) stabilized in shells of poly(N-vinylpyrrolidone) (PVP) are synthesized electrochemically by the benzimidazo[1',2':1,2]quinolino[4,3-b][1,2,5]oxodiazolo[3,4-f]quinoxaline (BIQOQ)-mediated reduction of Ag+ ions in the presence of PVP and cellulose nanofibers (NC) at the potential controlled at the BIQOQ– generation in the DMF/0.1 M Bu4NBF4 medium at room temperature. The mediator is not consumed in this process, the generated metal is not deposited on the cathode, being formed in solution volume in the quantitative yield corresponding to the theoretical quantity of electricity passed. The synthesized products represent cellulose nanofibers decorated most compactly with silver nanoparticles covered by PVP shells Ag@PVP/NC. The size of NP-Ag in Ag@PVP/NC (11 ± 3 nm) is much lower as compared with the Ag@PVP nanocomposite synthesized by the methyl-viologen‑mediated reduction of Ag+ ions under similar conditions in the absence of NC (20 ± 7 nm). The synthesized nanocomposite exhibits catalytic activity in the reactions of reduction of nitroaromatic compounds by sodium borohydride in aqueous media.