基于酵母的钨酸铋空心微球制备及其光催化降解盐酸四环素性能

Yeast-assisted synthesis of bismuth tungstate hollow microsphere and its photocatalysis for tetracycline hydrochloride

以酵母细胞为模板,Na_2WO_4·2H_2O和Bi(NO_3)_3·5H_2O为原料,采用生物模板法制备了钨酸铋(Bi_2WO_6)空心微球。运用X射线衍射(XRD)、扫描电镜(SEM)、能谱(EDS)、紫外-可见漫反射光谱(UV-vis DRS)、傅里叶变换红外光谱(FT-IR)和热重分析(TG-DTA)等技术对样品进行了结构与形貌表征,并以盐酸四环素为目标污染物,考察了Bi_2WO_6空心微球的光催化活性。结果表明:所制得的Bi_2WO_6空心微球系正交相Bi_2WO_6,直径约为2μm,颗粒形貌一致,较好的保持了酵母细胞椭圆形的形貌,在可见光区有吸收。在氙灯照射下,Bi_2WO_6空心微球对盐酸四环素的光催化效果显著,催化剂用量及溶液的pH值对四环素的降解率有影响,当催化剂浓度为1.0g/L,溶液pH值为3时,Bi_2WO空心微球对20mg/L的四环素光催化降解率可达95%以上。

Bismuth tungstate hollow microspheres were synthesized through biotemplate route by adopting yeast ceils as templates and Na2 WO4 · 2 H2O and Bi（NO3 ）3 ·5 H2O as raw materials. Several techniques were employed to characterize the as-prepared products,including X-ray diffraction, scanning electron microscope, energy spectrum, ultraviolet-visible diffuse reflection spectrum, fourier transform infrared spectroscopy, thermo gravimetric analysis and etc. And the photocatalysis of microspheres was evaluated through the degradation of tetracycline hydrochloride as the goal pollutant under xenon lamp. Results showed that the products were of orthorhombic bismuth tungstate. The morphology of samples was hollow microspheres with diameter of about 2μm which retained the features of yeast cells fairly well. And the microspheres showed light adsorption in visible area. The microspheres exhibited remarkable photocatalysis activity for tetracycline hydrochloride under xenon lamp exposure. And the photocatalytic parameters including catalyst dosage and the pH of the solution had impact on the degradation rate. The degradation rate for 20 mg/L tetracycline solution was over 95% when the catalyst dosage was 1.0g/L with pH at 3 in initial solution.