摘要
为实现纳米二氧化钛(TiO_(2))的回收和重复使用,采用静电纺丝、高温煅烧和酸溶技术制备了多孔碳纳米纤维(PCNF),随后使用二次形核法将锐钛矿相TiO_(2)负载到其表面,得到具有光催化活性的TiO_(2)/PCNF复合材料。通过扫描电子显微镜、X射线衍射仪、X射线光电子能谱仪、紫外-可见漫反射光谱仪等表征了TiO_(2)/PCNF复合材料的形貌结构、成分和光吸收性能,并测试了其对降解亚甲基蓝(MB)溶液的光催化性能。结果显示:复合材料的比表面积高达331.9 m^(2)/g,光照30 min后对MB溶液(5 mg/L)的去除率为98.6%,光照60 min后对MB溶液的去除率可达99.6%,均高于同等TiO_(2)含量的对比组;重复使用5次后,其对MB溶液的去除率仍然保持在95.0%;PCNF是一种性能优异的光催化载体材料,它不仅能够实现对纳米TiO_(2)的固定和回收,而且能提高TiO_(2)的光催化性能。
Objective With the widespread use of organic dyes,the residue of which have gradually become the main component of industrial wastewater and caused serious water pollution.As an environmentally friendly photocatalyst,titanium dioxide(TiO_(2))nanoparticles have been used in dye degradation,wastewater treatment and other fields due to their high photocatalytic activity,large specific surface area and easy preparation,but they also have problems such as wide band gap and difficult separation and recovery.Therefore,it is urgent to find a suitable carrier material to achieve effective separation and recovery of TiO_(2) without reducing its photocatalytic activity and stability.Method Porous carbon nanofibers(PCNF)were prepared by electrospinning,high-temperature calcination,and acid dissolution.Then anatase TiO_(2) was loaded onto its surface by secondary nucleation method to obtain photocatalytic TiO_(2)/PCNF composites.The morphology,structure,composition,and light absorption properties of TiO_(2)/PCNF nanocomposites were characterized by scanning electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy and UV-Vis diffuse reflection spectroscopy,and the photocatalytic properties of TiO_(2)/PCNF nanocomposites were tested by degradation methylene blue(MB)solution.Results SEM results showed that TiO_(2) nanoparticles were uniformly loaded on porous CNF surfaces,while it was difficult to be loaded on smooth CNF surfaces.This showed that the mesoporous surface of carbon nanofibers was the key to the loading of TiO_(2).XRD results indicated that the three samples prepared,i.e.,TiO_(2),TiO_(2)/PCNF and TiO_(2)/CNF were of anatase phase TiO_(2).Compared with rutile phase and titanite phase,anatase phase TiO_(2) had better photocatalytic activity,so it was beneficial to improve the photocatalytic performance of TiO_(2)/PCNF.The full spectrum of XPS showed that Ti,O,C,F and N elements existed in TiO_(2)/PCNF composites,which further proved that TiO_(2) had been successfully loaded onto the surface of porous carbon nanofibers.The UV-Vis DRS results showed that significant redshift could occur when TiO_(2) was loaded onto both PCNF and CNF surfaces,which not only increased the utilization rate of visible light,but also reduced the band gap value.Brunauer-Emmett-Teller(BET)results suggested that the prepared TiO_(2)/PCNF composites had mesoporous structures,and the specific surface area was as high as 331.9 m^(2)/g,providing abundant active sites for adsorption and surface reaction.The photocatalytic tests showed that the removal efficiency of TiO_(2)/PCNF composites was higher than that of the control group with the same TiO_(2) content.After 30 min illumination of TiO_(2)/PCNF composite material,the removal rate of MB solution of 5 mg/L was 98.6%,and after 60 min illumination,the removal rate of MB solution could reach 99.6%.However,the removal rates of TiO_(2) and TiO_(2)/CNF composites in the control group were only 93.3% and 73.2% for MB solution after 30 min illumination.After repeated use for 5 times,the removal rate of TiO_(2)/PCNF on MB solution remained at 95.0%.All these indicated that TiO_(2)/PCNF composites have excellent photocatalytic and reusable properties.Conclusion The TiO_(2)/PCNF composite was successfully prepared by secondary nucleation method,and the composite had excellent photocatalytic and reusable properties.Compared with CNF,it was found that PCNF with mesoporous structure was more conducive to the loading of TiO_(2).The improvement of photocatalytic performance of TiO_(2)/PCNF composites was mainly attributed to the following reasons.①All the prepared TiO_(2) were anatase phase,which has better photocatalytic activity than rutile phase and plate titanite phase.②The TiO_(2)/PCNF composite increased the response range of TiO_(2) to visible light,which was conducive to improve the utilization rate of TiO_(2) for visible light.③PCNF had excellent electrical conductivity,which was conducive to accelerating the separation of TiO_(2) photogenerated electrons and holes.④PCNF had a large specific surface area,which providing more active sites both for MB adsorption and surface reactions.
作者
陆瑶瑶
叶俊涛
阮承祥
娄瑾
LU Yaoyao;YE Juntao;RUAN Chengxiang;LOU Jin(Jiangxi Key Laboratory of Surface Engineering,Jiangxi Science and Technology Normal University,Nanchang,Jiangxi 330036,Chi)
出处
《纺织学报》
EI
CAS
CSCD
北大核心
2024年第4期67-75,共9页
Journal of Textile Research
基金
国家自然科学基金项目(51363008)。
关键词
有机染料
光降解
二氧化钛
静电纺丝
碳纳米纤维
亚甲基蓝
二次形核法
光催化性能
废水处理
organic dye
photodegradation
titanium dioxide
electrospinning
carbon nanofiber
methylene blue
secondary nucleation method
photocatalytic performance
wastewater treatment
