关键词: 纳微纤维膜, 氮化碳, 三相体系, 光催化性能, 染料降解

Abstract:

To enhance the photocatalytic degradation performance of the graphitic carbon nitride (g-C₃N₄), a bilayer micro/nanofiber membrane with opposing wettability has been developed via the electrospinning method, where the polystyrene membrane was used as the hydrophobic layer, and the g-C₃N₄/iron (II) phthalocyanine (FePc) heterojunction was taken for the hydrophilic layer on a polyacrylonitrile/polyvinylpyrrolidone membrane substrate. The morphology, chemical construction and optical absorption of the prepared bilayer membrane were investigated, and the photocatalytic performance for dye degradation was studied. The results indicate that the hydrophobic layer and the hydrophilic catalyst layer, with the water contact angle of 140° and 12°, respectively, can be tightly combined with each other. The distribution of g-C₃N₄/FePc on the catalyst layer is uniform, and the sensitization of FePc extends the optical absorption up to 800 nm. During the photocatalytic dye degradation, the hydrophobic layer can serve as gas passage to quickly deliver O₂ from air to the catalytic interface. This greatly boosts the capture of photoelectrons in conduction band of g-C₃N₄ by O₂ via constructing an air-liquid-solid triphase contact interface, resulting in 3.1 times fold higher reaction kinetics versus a normal diphase system.

Key words: micro-nanofiber membrane, carbon nitride, tri-phase system, photocatalytic performance, dye degradation