分级多孔结构ZnO的秸秆生物模板法制备及光催化性能

Hierarchical Porous ZnO Nanomaterial Synthesized with Corn Straw as Biological Templates and Its Photocatalytic Performance

以玉米秸秆为生物模板,经过焙烧工艺制备了具有秸秆分级多孔结构的ZnO纳米材料.利用X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、热重分析、氮气吸附-脱附分析(BET)、紫外-可见温反射光谱(UV-Vis-DRS)、X射线光电子能谱(XPS)等对样品的组成和微观结构进行表征.结果表明,通过模板法制备的ZnO为纤锌矿型,具有分级多孔结构,晶体粒径为46.2 nm,材料比表面积为32.8m^2/g.以亚甲基蓝为目标污染物,氙灯光照3.0 h后,采用模板法制备的ZnO对亚甲基蓝的降解率明显高于无模板ZnO,分别为98%和74%.研究了污染物浓度、催化剂投加量及重复使用对降解率的影响,结果表明,模板法制备的ZnO光催化性能稳定,可多次回收利用,重复使用5次后其降解率维持在95%.

Hierarchical porous ZnO nanomaterial was prepared using corn straw as biological template via roasting process.The components and crystal characterization of the material were investigated via X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),nitrogen adsorption-desorption analysis and UV-Vis spectrophotometry.The results show that the ZnO material synthesized by template method is wurtzite type.And the crystal particle size is 46.2 nm,the specific area is 32.8 m 2/g.Irradiated with Xenon lamp,the rate of decolorization of methylene blue of ZnO material prepared by template method reaches 98%,which is 1.3 times of that prepared without template(74%).Moreover,the influence of pollutant concentration and dosage of catalyst were also investiggted.And the results reveal that ZnO materials synthesized by template method own low grain size but high specific surface area,when 0.15 g catalyst was used to degrade 100 mL of 20 mg/L(MB)solution for five times,the degration rate remained at 95%.