Enhancing mechanical and photocatalytic properties by surface microstructure regulation of TiO2 nanofiber membranes

Abstract

In this work, TiO2 nanofiber membrane (NFM) with a complete surface microstructure was prepared through regulating the surface microstructure of TiO2 NFM by doping Zr. The crystal structures and morphological analyses indicated that the nanofiber membranes were consisted by disordered accumulation of Zr-doped TiO2 nanofibers with a crack-free surface, small grain size and high aspect ratio. When the doping amount of Zr was 0.8 mL, the tensile strength of the doped membranes reached 1.27 MPa, which was 60.7% higher than that of pure TiO2 NFM. The photocatalytic performance of Zr-doped TiO2 NFM was evaluated by the degradation performance of Methylene orange (MO) under simulated sunlight irradiation. Compared with the undoped TiO2 NFM, the 0.8-Zr/TiO2 NFM presented a higher catalytic degradation efficiency (improved by 69.6%), and the photocatalytic performance maintained stable after five circulating. It was found that the doping of Zr ions effectively limited the surface crack size and grain size of TiO2 nanofibers, thereby improving the tensile strength, and enhanced the surface area effect and carrier transfer efficiency of TiO2 NFM. On the other hand, a narrow band-gap was obtained by doping a small amount of Zr ions, which expanded the visible light response range to improve the photocatalytic performance of TiO2 nanofibers.