摘要：

通过简单的溶剂热法将球形BiOBr固定在电纺聚乙烯醇（PVA）/SiO₂有机-无机杂化纳米纤维上，制备了柔性PVA/SiO₂@BiOBr纳米纤维。电纺PVA/SiO₂纳米纤维由Si—O—C—O—Si键桥链接而成，具有良好的机械强度、耐溶剂性和耐热性，且其表面含有未交联羟基，可为BiOBr晶体的生长提供成核位点，无需额外的表面改性，是合适的BiOBr载体。PVA/SiO₂@BiOBr纳米纤维与粉体BiOBr相比，由于可见光捕获能力的提高以及暴露的活性位点数量的增加，其对罗丹明B（RhB）表现出更强的可见光催化活性，可见光照射180 min后，RhB的降解率可达约63%，光催化降解速率是粉体BiOBr的2.1倍。此外，PVA/SiO₂@BiOBr纳米纤维表现出良好的稳定性和可重复使用性，3次循环后光催化活性仅降低了约5%，同时光催化剂所具有的柔韧性使其回收过程方便，可直接从水中夹取。

关键词: 静电纺丝, 光催化, 罗丹明B, 溴氧化铋, 纳米纤维

Abstract:

Sphere-like BiOBr was immobilized on electrospun polyvinyl alcohol（PVA）/SiO₂ organic-inorganic hybrid nanofibers by simple solvothermal route，resulting in flexible PVA/SiO₂@BiOBr nanofibers. Electrospun PVA/SiO₂ nanofibers，in which PVA chains and silica network crosslink via Si—O—C—O—Si bridges，exhibited high mechanical strength along with good solvent resistances and thermal stability. Moreover，the active hydroxyl groups of PVA that did not react with tetraethyl orthosilicate（TEOS） could provide nucleation sites for BiOBr crystals growth，thus additional surface modifications could be avoided. Compared with powdered BiOBr，the PVA/SiO₂@BiOBr nanofibers exhibited enhanced visible light driven photocatalytic activity due to the improvement of visible light harvesting ability and the increase of exposed active sites. After visible light irradiation for 180 min，the removal rate of Rhodamine B（RhB） over PVA/SiO₂@BiOBr was about 63% and the photocatalytic degradation rate was 2.1 times that of powdered BiOBr. In addition，PVA/SiO₂@BiOBr nanofibers showed good stability and good reusable property. The photocatalytic activity was only reduced by about 5% after three cycles. Meanwhile，it was convenient to recover the photocatalysts due to their flexibility and they could be directly reclaimed from water.

Key words: electrospinning, photocatalysis, Rhodamine B, BiOBr, nanofibers

中图分类号: 

• TQ340.64

• O643.36

• X703.1