基于双层微纳米纤维膜的气液固三相体系构建及其光催化性能

为提升石墨相氮化碳(g-C₃N₄)的光催化降解性能,通过静电纺丝技术制备了亲疏不对称的双层纳微纤维膜,其中疏水层为聚苯乙烯纤维膜,亲水层为以聚丙烯腈/聚乙烯吡咯为载体的g-C₃N₄/酞菁铁(FePc)异质结催化膜,对其表面形貌、化学结构和光吸收性能进行表征,并考察了对染料废水的光催化降解作用。结果表明:水接触角分别为140°和12°的疏水层和亲水催化层可紧密结合,其中催化层中g-C₃N₄和FePc在纤维膜上分布均匀,且FePc的引入将纤维膜的光吸收范围拓展至800 nm;在染料的光催化降解中,疏水层可作为气体通道将空气中的O₂传输至亲水催化层,从而形成气液固三相接触的反应体系,有效促进O₂对g-C₃N₄导带光生电子的俘获,使其光催化活性较常规二相体系提升3.1倍。

Construction of air-liquid-solid tri-phase system from bilayer micro/nanofiber membrane and its photocatalytic performance

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.