Photo-induced disinfection property and photocatalytic activity based on the synergistic catalytic technique of Ag doped TiO₂ nanofibers

Various metal-doped TiO₂ nanofibers were prepared by hydrothermal synthesis followed by the thermal treatment in air. An array of metal dopants including Ag, Au, Co, Cr, Cu, Fe, Ni, Pd, Pt, Y, and Zn, were respectively doped into TiO₂ NFs to acquire the visible-light photocatalytic activity. Considering the photodegradation results under visible-light illumination, Ag doped TiO₂ NFs was chosen to study further. Then, the optimal doping level and calcination process were studied systemically to obtain the highly visible light active Ag doped TiO₂ NFs. As the Ag doping concentration increased up to 5.00 mol%, anatase to rutile phase transition was observed. Meanwhile, based on the consistent results of synchrotron X-ray spectra, element analysis, and morphological observation, Ag₂O was detected and located on the surface of as-synthesized Ag doped TiO₂ NFs. Thus, the photodegradation of methyl orange by using 5.00 mol%-Ag doped TiO₂ NFs calcined at 600 °C performed the highest visible-light photodegradation activity. Moreover, it also showed the excellent disinfection against E. coli and S. aureus under visible light due to the synergistic effect of Ag₂O and photo-induced reactive oxygen species (ROS) formed by TiO₂ photocatalyst. The synthesized Ag doped TiO₂ NFs makes large-scale and convenient fabrication possible, and it has tremendous practical potentials in the photodegradation of environmental pollution and disinfects bacteria behavior.