改性聚丙烯腈纤维负载MoSx/TiO2光催化材料制备及其降解染料性能

为提升MoS_x/TiO₂异质结的光催化性能,使用偕胺肟改性的聚丙烯腈(PAN)纤维作为载体,先通过静电结合及原位转化负载MoS_x,再通过配位作用结合TiO₂合成了复合光催化剂。分析了该催化剂的表面形貌、化学结构和光吸收性能,并考察了其在可见光下对印染废水的处理效果。结果表明:MoS_x和TiO₂可均匀分布于PAN纤维表面,且MoS_x的引入大幅提升了催化剂的光吸收性能,并能够在波长大于500 nm的可见光下快速氧化降解染料废水,其反应速率常数达到单独负载TiO₂纤维催化剂的4.7倍;该催化剂具有优异的重复使用性能,其高活性主要来源于MoS_x对污染物的强吸附能力及其在可见光下对TiO₂的敏化作用。

Preparation of modified polyacrylonitrile fiber supported MoSx/TiO2 composite photocatalyst and its performance for dye degradation

To improve the photocatalytic performance of MoS_x/TiO₂ heterojunction, amorphous MoS_x was anchored onto amidoximated polyacrylonitrile (PAN) fiber via an adsorption and in-situ transformation method, and then TiO₂ was immobilized onto the fibrous support in order to synthesize a composite photocatalyst. The morphology, chemical structure and optical property of the photocatalyst were investigated, and its photocatalytic performance on the oxidation of dye wastewater was evaluated under visible light irradiation. The results show that MoS_x and TiO₂ can be uniformly distributed onto the fibrous surface, and the MoS_x significantly enhances the light absorption of the photocatalyst. The as-prepared photocatalyst could achieve the fast oxidative degradation of the dye wastewater under light irradiation with wavelength greater than 500 nm, resulting in a 4.7-fold higher reaction kinetics versus the reaction system over single TiO₂ supported fibrous photocatalyst. In addition, the photocatalyst exhibited high recycling ability for dye degradation. This high photocatalytic activity mainly originates from the enhanced adsorption performance towards pollutants by MoS_x, as well as the sensitization effect of MoS_x to TiO₂ under visible light irradiation.