Self-Regeneration Performance and Characterization of Silver-Containing Activated Carbon Fibers Coated by Titanium Dioxide

In this study, wood-based activated carbon fibers (WACF) were modified by Ag nanoparticles (AgNPs) and TiO(2) films. The coating of TiO(2) films decreased the AgNPs agglomeration and exfoliation on WACF. As the soaking concentration of AgNO(3) solution (S(conc)) increased, AgNPs size and content increased, while the pore volume (especially micropore volume) of fibers reduced. However, at higher S(conc) in the range of 0.2 to0.4 mol/L, only slight variations in AgNPs content and pore structure were observable for WACF/TiO(2)/Ag (Ag-containing WACF coated by TiO(2) film). WACF/TiO(2)/Ag-0.1 (0.1 was the soaking concentration of AgNO(3) solution, mol/L) represented the best self-regeneration performance under the visible light irradiation. The self-regeneration performance of WACF/TiO(2)/Ag was determined by the synergistic effects of two factors: adsorption and photodegradation. The abundant pores of WACF/TiO(2)/Ag-0.1 increased the methylene blue (MB) concentration of TiO(2) surrounding and facilitated the MB photodegradation. Meanwhile, their suitable Ag content enhanced MB photodegradation. Furthermore, the principal pathway of a chemical reaction between Ag(+) and WACF was interpreted based on the data of surface elemental constituents and surface functional groups.