【作者】 章晓彤；

【导师】 周国伟；

【作者基本信息】 山东轻工业学院 ， 应用化学， 2010， 硕士

【摘要】 本论文通过改进的溶胶–凝胶法分别合成出了氮、镧共掺杂纳米二氧化钛光催化材料,以Brij98(脂肪醇聚氧乙烯醚,C18H35(OC2H4)20OH)和CTAB(十六烷基三甲基溴化铵)作为复合模板剂合成出氮、镧共掺杂和氮、铈共掺杂介孔二氧化钛光催化剂复合材料以及用旋转涂膜法制备出介孔二氧化钛薄膜材料。运用X–射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅立叶变换红外光谱(FT–IR)、能量分散X–射线光谱(EDS)、紫外可见漫反射吸收光谱(UV–vis DRS)、X–射线光电子能谱(XPS)以及N2吸脱附等表征手段对所制备材料进行了详细的分析和研究。结果显示,合成样品的XRD谱图均呈现锐钛矿型晶体结构;TEM图片显示有较为明显的孔道结构;SEM可以看到薄膜材料表面非常光滑平整;FT–IR、EDS和XPS谱图分析都显示氮、镧、铈这些所掺杂的离子均能有效的掺杂进入二氧化钛中;UV–vis DRS分析结果说明通过进行掺杂改性的二氧化钛复合材料的光谱响应范围有效的向可见光转移,吸收峰发生了明显的红移,从而提高了其对可见光的利用率,扩大了其实际应用的范围。对所制得样品的光催化性能研究是通过以甲基橙、生活污水以及制浆造纸废水为目标降解物来进行的,并分别在紫外光和模拟可见光下对样品材料进行了研究。结果显示,共掺杂改性之后的二氧化钛纳米颗粒、介孔材料以及薄膜材料在紫外和可见光下都比纯二氧化钛具有更高的光催化活性。分别对共掺杂离子的摩尔比例、复合模板剂之间的比例关系、光照时间等因素进行了研究。在紫外光和模拟可见光照射下,N(0.020)La(0.012)TiO2纳米颗粒对甲基橙的降解率分别达到了100%和97.2%,而在紫外光照射下,对生活废水色度的去除率达到100%,CODcr(化学需氧量)去除率达到69.7%。在紫外光照射下,复合模板剂摩尔比例Brij 98:CTAB = 1:1时制备的介孔二氧化钛样品显示出了最好的光催化活性,制浆造纸废水CODcr去除率达到73%,色度去除率达到100%。在紫外条件下,介孔二氧化钛薄膜材料对甲基橙的光催化降解达到100%。更多还原

【Abstract】 Using composite surfactant templates polyoxyethylene (20) oleyl ether (Brij98) and cetyl trimethyl ammonium bromide (CTAB) as structure–directing agents, N/La, and N/Ce co–doped mesoporous TiO2 complex photocatalysts and films were synthesized successfully by a modified sol–gel process using tetrabutyl titanate as the inorganic precursor, and urea, lanthanum nitrate and cerium nitrate as doping ion donors. The micromorphology of co–doped mesoporous TiO2 samples were characterized by X–ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), fourier transformed infrared spectroscopy (FT–IR), UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS), energy–dispersive X–ray spectrometer (EDS), X–ray photoelectron spectroscopy (XPS) and N2 adsorption–desorption measurements. The XRD results indicated that all the the prepared complex photocatalyst were anatase. The TEM showed that the samples had mesoporous structures. The SEM indicated that the mesoporous TiO2 films possessed smooth surface. The FT–IR, EDS and XPS results showed that nitrogen, lanthanum and cerium had have been effectively doped into the titania lattice. The UV–Vis analysis revealed a red shift in the absorbing band edge within the range of 400–500 nm, which enhanced the usage of sunlight for the modified TiO2.The photocatalytic activities of samples were measured by photodecomposition of methyl orange (MO) and papermaking wastewater in both UV and visible light. The percent degradation of methyl orange (MO) was ca. 97.2% for the optimum co–doping of N(0.020)La(0.012)TiO2 under simulated sunlight irradiation for 9 h. The improvement of the photocatalytic activity was ascribed to the synergistic effects of the nitrogen and lanthanum co–doping. The mesoporous TiO2 sample with molar ratio of Brij98:CTAB=1:1 exhibited the highest photocatalytic activity for degradation of papermaking wastewater under ultra–violet light irradiation. The chemical oxygen demand (CODcr) percent degradation was about 73% in 12 h and chroma percent degradation was 100% in 8 h. The photocatalytic activities of mesoporous TiO2 flims were measured by photodecomposition of 2 mg·L-1 methyl orange, and the percent degradation was 100% after UV light irradiation 2 h.更多还原