Functional cellulose-based nanofibers with catalytic activity: Effect of Ag content and Ag phase

The cellulose acetate nanofibers containing Ag ions [CA(as-spun)] were fabricated by electrospinning a CA solution with 0-5 wt% AgNO3. The CA(as-spun) was UV-irradiated to produce CA nanofibers containing Ag ions/nanopaticles (NPs) [CA(UV)], and the CA(UV) was deacetylated to cellulose nanofibers with Ag NPs [CA(UV + DA)]. When the CA(UV) was deacetylated with KOH/ethanol solution, the number and size of the Ag NPs were further increased. During the deacetylation reaction, residual Ag+ ions in the CA(UV) seemed to be reduced by hydroxide anions in KOH/ethanol solution and Ag NPs seemed to be diffused and aggregated further in the cellulose nanofibers. The catalytic activity of cellulose-based nanofibers with different Ag contents or phases was investigated using a reduction of methylene blue (MB) as a model reaction. From a model reaction, Ag ions played an important role as a reducing catalyst of MB.