The structure and self-regeneration performance of Salix psammophila-activated carbon modified by Ag and N co-doped TiO2

Abstract

In this study, Salix psammophila activated carbon (AC) was modified by immersing it in an AgNO₃ solution and coating it with an N-doped TiO₂ film to improve its self-regeneration performance in visible light. Ag⁺ was adsorbed and reduced to Ag nanoparticles by AC. Ti element only existed as Ti⁴⁺, and N element was incorporated into TiO₂ mainly in the form of interstitial nitrogen. The photodegradation of Ag-N-TiO₂-AC (AC coated with Ag and N co-modified TiO₂) was enhanced under visible light irradiation because of its three inherent structures: (1) Ag and N co-modified TiO₂ had a smaller average crystal size; (2) with a low bandgap (1.59 eV), the photoresponse region of Ag and N co-modified TiO₂ was greatly extended; (3) the lifetime of the photogenerated holes was increased. With the increase in the AgNO₃ dosage, the Ag-N-TiO₂-AC photodegradation increased, while its adsorption decreased. Because of these synergistic effects, 0.05Ag-0.1N-TiO₂-AC (where 0.05 is the dosage of AgNO₃, g) presented the best self-regeneration performance under visible light irradiation.