Near-field electrospinning of PTFE/ZnO membrane with regular pore geometry and its photocatalytic performance

Poly(tetrafluoroethylene) (PTFE) membrane is remarkable due to its impressive comprehensive properties. However, the PTFE membrane's chemical inertness and low surface energy make it difficult to achieve pore geometry regulation and functional modification. In this work, the PTFE/ZnO photocatalytic fiber membrane with regular membrane pore geometry was prepared by Near-filed electrospinning (NFES) technology. The precursor Zn(Ac)2 was added to the PTFE/poly(ethylene oxide) (PEO) spinning solution to introduce the ZnO seed layer. Then ZnO was grown in situ by hydrothermal method to prepare the NFES PTFE/ZnO membrane. The effects of the mass ratio of the PTFE/PEO spinning solution and the additional amount of Zn(Ac)2 on the membrane morphologies were investigated, and the effects of different membrane pore geometries on the photocatalytic degradation of methylene blue (MB) dye wastewater were discussed. The results showed that when the mass ratio of PTFE/PEO was 5:1 and the addition amount of Zn(Ac)2 was 15 wt%, the membrane had the optimal morphology. Compared with the PTFE/ZnO membrane prepared by electrospinning, the NFES PTFE/ZnO membrane with regular membrane pore geometry had more catalyst loading, and the dynamic MB removal rate reached 97.6% after 4 h of UV irradiation. After 5 cycles of testing, the degradation rate of MB can also reach 70.8%.