One-dimensional porous Ag/AgBr/TiO2 nanofibres with enhanced visible light photocatalytic activity.

One-dimensional (1D) Ag/AgBr/TiO₂ nanofibres (NFs) have been successfully fabricated by the one-pot electrospinning method. In comparison with bare TiO₂ NFs and Ag/AgBr/PVP (polyvinylpyrrolidone) NFs, the 1D Ag/AgBr/TiO₂ NFs photocatalyst exhibits much higher photocatalytic activity in the degradation of a commonly used dye, methylene blue (MB), under visible light. The photocatalytic removal efficiency of MB over Ag/AgBr/TiO₂ NFs achieves almost 100 % in 20 min. The photocatalytic reaction follows the first-order kinetics and the rate constant (k) for the degradation of MB by Ag/AgBr/TiO₂ NFs is 5.2 times and 6.6 times that of Ag/AgBr/PVP NFs and TiO₂ NFs, respectively. The enhanced photocatalytic activity is ascribed to the stronger visible light absorption, more effective separation of photogenerated electron-hole pairs, and faster charge transfer in the long nanofibrous structure. The Ag/AgBr/TiO₂ NFs maintain a highly stable photocatalytic activity due to its good structural stability and the self-stability system of Ag/AgBr. The mechanisms for photocatalysis associated with Ag/AgBr/TiO₂ NFs are proposed. The degradation of MB in the presence of scavengers reveals that h⁺ and ^•O⁻ ₂ significantly contribute to the degradation of MB. [ABSTRACT FROM AUTHOR]