α-Bi_2O_3纳米纤维的制备及其光催化性能研究

Preparation and photocatalytic property of α-Bi_2O_3 nanofibers

采用静电纺丝法制备了α-Bi_2O_3纳米纤维,并研究了煅烧温度对其形貌和光催化活性的影响。利用X射线衍射(XRD)、扫描电镜(SEM)、紫外可见漫反射光谱(UV-vis DRS)、热重-差热分析(TG-DTA)和N2吸附-脱附等温线(BET)等技术对样品进行了表征。以罗丹明B(RhB)和四环素(Tc)为降解模型,评价了Bi_2O_3纳米纤维材料的光催化性能。结果表明,前驱体复合纤维PVP/Bi(NO3)3在空气氛围下经450℃、500℃和550℃煅烧处理后,其产物Bi_2O_3的晶型均为单斜相α-Bi_2O_3。随着煅烧温度的升高,Bi_2O_3的形貌由直径较细的纤维(～100nm)逐渐变粗(～150nm),最后断裂成球状颗粒。发现经450℃煅烧温度处理得到的α-Bi_2O_3纤维具有最佳的可见光催化活性,在氙灯(150 W)照射下,180min,对RhB和Tc的降解率分别达到98.1%和94.5%。

α-Bi2O3 nanofibers were prepared by electrospinning,and with the effects of the calcination temperature on morphology and photocatalytic activity of theα-Bi2O3 nanofibers studied.The samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),thermogravimetric differential-thermal analysis(TG-DTA),ultraviolet-visible diffuse reflection spectrum(UV-vis DRS)and N2 adsorption desorption isotherm(BET),respectively.The photocatalytic properties of the prepared samples were evaluated by photocatalytic degradation of Rhodamine B(RhB)and tetracycline(Tc),which were used as the degradation models.The results showed that the crystal structure of Bi2O3 samples was all monoclinic phaseα-Bi2O3 after calcining the composite of fiber precursor PVP/Bi(NO3)3at 450℃,500℃ and 550℃in air atmosphere.In addition,the morphology of Bi2O3 samples was gradually changed from small diameter fiber(~100nm)to crude(~150nm),and finally broken into spherical particles at 550℃with the increase of calcination temperature.It was also found that the Bi2O3 nanofiber obtained at 450℃exhibits the excellent visible-light photocatalytic activity for the degradation of RhB and Tc with the degradation rates of 98.1%and 94.5% within 180 min under Xe lamp(150W)irradiation.