二氧化钛介孔微球的纳米金修饰及对其催化性能的影响

发布时间：2018-06-10 12:41

  本文选题：纳米复合材料 + 金　； 参考：《环境科学与技术》2017年S1期

【摘要】：染料污染和大气中CO排放已成为日益严重环境问题,研发染料污染物的降解技术及低温CO催化氧化有助于解决上述问题。利用高分辨透射电子显微镜(HRTEM)和X射线衍射(XRD)等技术,该文比较了二氧化钛(TiO_2)介孔微球修饰金(Au)纳米颗粒前后的形貌、结构与组成的变化及催化染料降解和低温CO氧化的性能。结果表明,应用沉积-沉淀法可将Au纳米颗粒均匀地修饰在TiO_2介孔微球表面,颗粒直径约为4.5 nm。XRD结果显示Au~(3+)被还原为单质Au,且还原过程没有破坏TiO_2载体的晶体结构;电感耦合等离子体质谱(ICP-MS)测试得出Au含量仅为3.12%。氮气吸附-脱附等温曲线测试出Au/TiO_2比表面积为103.6 m~2/g,相应的Barret-JoynerHalenda(BJH)孔径分布测试出平均孔径为9.3 nm。有机染料罗丹明B(Rh B)的光催化降解结果显示,Au/TiO_2复合催化剂催化下的降解速率为6.63×10-5s-1,而单一TiO_2催化下的降解速率为5.18×10~(-5)s~(-1)。亚甲基蓝(MB)光降解实验显示出相同的结果,进一步证明Au/TiO_2复合催化剂具有较高的活性。低温催化CO氧化测试结果表明,单一TiO_2不具有催化活性,Au/TiO_2催化作用时在室温下CO转化率达48%,升温至50℃时CO转化率可达到99%,显示出很高的催化活性和热稳定性,并且可重复利用。可见,纳米Au/TiO_2复合催化剂在处理有机染料污染和低温CO氧化方面具有潜在的应用价值。
[Abstract]:Dye pollution and CO emission in the atmosphere have become increasingly serious environmental problems. Research and development of degradation technology of dye pollutants and catalytic oxidation of CO at low temperature will help to solve these problems. By means of high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD), the morphology, structure and composition of TIO _ 2 / TIO _ 2 mesoporous microspheres modified with au) nanoparticles were compared, as well as the catalytic degradation of dyes and the performance of CO oxidation at low temperature. The results show that au nanoparticles can be uniformly modified on the surface of TiO2 mesoporous microspheres by deposit-precipitation method. The particle diameter is about 4.5nm.XRD. The results show that Au~(3) is reduced to au, and the crystal structure of TiO2 support is not destroyed during the reduction process. The results of inductively coupled plasma mass spectrometry (ICP-MS) show that the au content is only 3.12%. The specific surface area of Au/ TiO-2 is 103.6 mm2 / g, and the corresponding Barret-Joyner Halenda (BJH) pore size distribution is 9.3 nm. The photocatalytic degradation of organic dye Rhodamine (Rh B) shows that the degradation rate of Au/ TiO-2 composite catalyst is 6.63 脳 10 ~ (-5) s-1s ~ (-1), while that of a single TIO _ (2) catalyst is 5.18 脳 10 ~ (-10) ~ (-5) ~ (-1) ~ (-1) ~ (-1). The results of methylene blue MB-based photodegradation showed the same results, which further proved that the Au/ TiO-2 composite catalyst had higher activity. The results of low temperature catalytic CO oxidation test showed that TiO2 had no catalytic activity. The CO conversion reached 48 at room temperature and 99 at 50 鈩，

本文编号：2003260