An Effective Producing Method of Nanocomposites of Ag, Au, and Pd Nanoparticles with Poly(N-vinylpyrrolidone) and Nanocellulose

The preparation of Ag, Au, and Pd nanoparticles (NPs) by methylviologen (MV2+) was investigated-mediated electrochemical reduction of 1.5 mM Ag(I), Au(I), and Pd(II), respectively, in the presence of poly(N-vinylpyrrolidone) (PVP) and nanocellulose (NC) at the controlled potential of MV+ radical cation generation in aqueous medium at room temperature. Au(I) and Pd(II) ions were added to the solutions as chloride salts and Ag(I) by in situ dissolving of the Ag-anode during electrolysis. Metal ions are reduced quantitatively to M-0 when the theoretical amount of electricity was passed. Dispersion of the Ag anode along with dissolution results in a current yield of Ag-0 166%. The result of the synthesis is the nanocomposites of spherical Ag (288 nm), Au (103 nm), and Pd (5 +/- 1 nm) NPs encapsulated in the PVP shell, which are bound on the NC surface and dispersed in the solution volume. The dimensions of the Ag, Au, and Pd crystallites are in the range of values 7.14 divided by 14.4, 5.7 divided by 9.0, and 4.5 divided by 6.2 nm, respectively. The Pd nanocomposite shows a high catalytic activity increasing in time; the Ag and Au nanocomposites are significantly less active in the test reaction of p-nitrophenol reduction with sodium borohydride in an aqueous medium. When cetyltrimethylammonium chloride (CTAC) is added to the nanocomposites, the catalytic reaction rate increases by 57, 2.5, and 1.2 times for Ag, Pd, and Au nanocomposites, respectively.

Automated summary

The synthesis of Ag, Au, and Pd nanoparticles through electrochemical reduction mediated by methylviologen was investigated, leading to nanocomposites with different catalytic activities. The addition of cetyltrimethylammonium chloride (CTAC) significantly enhanced the catalytic reaction rates of Ag, Pd, and Au nanoparticle composites, showing increased efficiency in the test reactions.