单壁碳纳米管显著增强的ZnO可见光催化活性

摘要

Nanocomposite ZnO/SWNTs of zinc oxide (ZnO) and single-walled carbon nanotubes (SWNTs) were fabricated by a sol-gel method using Zn(CH3COO)2·2H2O as raw material. The samples were characterized by X-ray diffraction spectroscopy, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, Fourier transformed infrared spectroscopy and ultraviolet-visible spectroscopy. The results show that ZnO nanoparticles with the size of about 10- 20 nm are closely deposited on the sidewalls of SWNTs and the nanocomposite presents enhanced absorption ability in the visible region. The composite exhibits a dramatically improved photocatalytic activity to decompose methyl orange and methylene blue in aqueous solutions under natural light. The photodegradation rate for methyl orange is 99.8% after 200 min, which is about 20 times that of pure ZnO (4.8%). For methylene blue, the degradation rate reaches 98.4% after 20 n min, which is about 25 times that of pure ZnO (4.0%).%利用醋酸锌为原料，采用溶胶-凝胶法制备了单壁碳纳米管（SWMTs）和氧化锌的纳米复合物（ZnO/SWNTs）。用X射线衍射光谱（XRD）、拉曼光谱、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、热重分析（TGA）、傅里叶变换红外光谱（FT-IR）以及紫外-可见吸收光谱（UV-Vis）对复合物进行了表征。结果显示，粒径为10～20 nm的ZnO粒子均匀地负载在SWNTs表面，且在可见光区具有很好的光吸收性能。研究了ZnO/SWNTs光催化剂在太阳光照射下对甲基橙和亚甲基蓝的光催化降解情况。结果表明，复合物的催化活性明显高于ZnO。对于甲基橙，光照200 min后，降解率为99.8%，是纯ZnO（4.8%）的20倍；对于亚甲基蓝，仅光照20 min，降解率就达到了98.4%，是纯ZnO（4.0%）的25倍。