柔性电纺BiOCl@PAN/TiO_(2)纳米纤维光催化还原水中Cr(VI)

Flexible electrospun BiOCl@PAN/TiO_(2) nanofibers for enhanced photocatalytic reduction of Cr(VI)in water

为改善纳米TiO_(2)的光催化活性和可回收性,采用静电纺丝技术制备了柔性PAN/TiO_(2)纳米纤维,再通过溶剂热法在纤维表面负载BiOCl,构筑了BiOCl@PAN/TiO_(2)复合纳米纤维光催化剂,并考察了其对水相中Cr(VI)的光催化还原性能.结果表明,BiOCl均匀致密地负载在预先热氧化稳定(TOS)处理的PAN/TiO_(2)纳米纤维表面,TOS处理不仅可以改善PAN/TiO_(2)的物理化学性质,提高其稳定性,还能使TiO_(2)颗粒向纤维表面迁移,从而与BiOCl形成异质结构.所制备的BiOCl@PAN/TiO_(2)复合纳米纤维具有良好的可见光响应性,光生电子空穴对复合率低,对水相中Cr(VI)表现出增强的光催化活性,可见光照射下180 min内对Cr(VI)的光催化还原效率达到81%,且拥有良好的稳定性和可回收性.5次循环后,光催化活性仅降低了5%左右,反应后光催化剂回收方便.本研究为基于TiO_(2)的高效可持续光催化剂的设计开发提供了一种新的策略.

In this work,in order to enhance the photocatalytic activity and recyclability of nano TiO_(2),flexible PAN/TiO_(2) nanofibers were fabricated using electrospinning technique.Subsequently,BiOCl was loaded onto the fiber surfaces through solvothermal method,constructing BiOCl@PAN/TiO_(2) composite nanofiber photocatalysts.The photocatalytic reduction performance of the composite nanofibers towards Cr(VI)in aqueous solution was investigated.The results demonstrated that BiOCl was uniformly and densely loaded on the surfaces of PAN/TiO_(2) nanofibers pretreated with thermal oxidation stabilization(TOS).TOS treatment not only improved the physicochemical properties and stability of PAN/TiO_(2),but also induced the migration of TiO_(2) particles towards the fiber surfaces,thus forming a heterogeneous structure with BiOCl.The prepared BiOCl@PAN/TiO_(2) composite nanofibers exhibited excellent visible light responsiveness and low recombination rate of photogenerated electron-hole pairs.They showed enhanced photocatalytic activity towards Cr(VI)in aqueous solution under visible light irradiation,achieving a photocatalytic reduction efficiency of 81%within 180 minutes.Furthermore,the composite nanofibers demonstrated good stability and recyclability,with only a slight decrease of around 5%in photocatalytic activity after five cycles.The photocatalysts were also conveniently recovered after the reaction.This work provides a new strategy for the design and development of efficient and sustainable TiO_(2)-based photocatalysts.