ZnO纳米管的光学性质及其对甲基橙降解的光催化活性

以十二烷基硫酸钠为模板剂采用水热法合成了ZnO纳米管,以尿素和ZnSO4为原料制备了ZnO纳米颗粒,并应用透射电镜、x射线衍射、光致发射光谱、拉曼光谱、比表面积测定、傅里叶红外光谱和紫外-可见漫反射光谱等技术对样品进行了表征.结果表明,ZnO纳米管的比表面积较大,在λ≈650nm的可见光波段ZnO纳米管开始出现吸收峰,而ZnO纳米颗粒在可见光波段几乎没有吸收.ZnO纳米管和纳米颗粒在紫外光照射下均对甲基橙有降解作用,其中ZnO纳米管的光催化活性较高.随着催化剂用量的增加和光照时间的延长,甲基橙降解率逐渐提高;甲基橙浓度的增大使甲基橙降解率降低.

Optical Properties of ZnO Nanotubes and Their Photocatalytic Activity for Degradation of Methyl Orange

ZnO nanotubes were synthesized by the hydrothermal method using sodium dodecyl sulfate as the template, and ZnO nanopar-tides were prepared with urea and ZnSO_4 as raw materials. The optical properties and photocatalytic activity of ZnO nanotubes and nanopar-ticles were studied, and the samples were characterized by transmission electron microscopy, X-ray diffraction, photoluminescence spec-troscopy, Raman spectroscopy, specific surface area determination, Fourier transform infrared spectroscopy, and ultraviolet-visual diffuse reflection spectroscopy. The ZnO nanotubes had larger specific surface area than the ZnO nanoparticles. The absorption peak of ZnO nanotubes began to appear atλ≈650 nm, but the ZnO nanoparticles nearly had no absorptive capacity in the visible band. ZnO nanotubes and nanoparticles can degradate methyl orange under ultraviolet light, and the catalytic activity of ZnO nanotubes was greater than that of ZnO nanoparticles. With the increase in the catalyst amount and illumination time, the degradation rate of methyl orange increased. Increasing the methyl orange concentration reduced the degradation rate.