Porous Nanofibers Formed by Heterogeneous Growth of ZnO/Ag Particles and the Enhanced Photocatalysis

Porous ZnO/Ag nanofibers with unique multi-interface contact structures have been synthesized by an electrospinning method. The composite nanofibers with the length of several hundred micrometers are composed of uniformly distributed ZnO and Ag nanoparticles in the size range 10~30 nm. Notably, a heterogeneous growth in the interface of ZnO and Ag particles occurs. The MO degradation rate of ZnO/Ag nanofibers with Ag content of 18 wt.% is 100% in 10 min under UV-vis irradiation and that of ZnO/Ag nanofibers with Ag content of 15 wt.% is 92% in 40 min under simulated day light, which is two times that of the pure ZnO. It is attributed to a special structure that improves the generation and separation efficiency of the photo-generated charges by the expansion of the absorption edges, the utilization efficiency of the surface plasmon resonance (SPR) oscillations of Ag, and the effective transferring of electrons from ZnO through the heterogeneous-growth interface. No obvious loss of the photocatalytic activity is observed after five cycles, indicating the excellent photostability of ZnO/Ag nanofibers. The work sheds light on the structure design of highperformance composite photocatalysts.