【作者】 薛彩红；

【导师】 侯新刚；

【作者基本信息】 兰州理工大学 ， 材料学， 2008， 硕士

【摘要】 近年来,纳米TiO₂粉体作为一种新型光催化剂,已成为超细粉体合成的一个研究热点。因其具有价廉、无毒、稳定性高、能够再生循环利用等优点,广泛应用于废水处理、气体净化、杀菌防污、自洁装饰材料等。本文主要研究了纳米TiO₂粉体的制备,并通过X射线衍射仪、透射电子显微镜、差热分析仪、红外拉曼光谱仪等手段对制得的粉体进行微观性能测试和表征,还通过掺杂等方式提高了粉体的催化活性。采用沉淀法制备TiO₂粉体,在制备过程中加入阳离子表面活性剂（十六烷基三甲基溴化铵）、阴离子表面活性剂（十二烷基硫酸钠、十二烷基苯磺酸钠）,均能有效降低团聚现象。其中十二烷基苯磺酸钠分散性能最好,粉体平均粒径为32nm,并且分布均匀。而以十六烷基三甲基溴化铵为表面活性剂制备的TiO₂粉体平均粒径为64nm,团聚相对严重,粒径分布较宽。采用溶胶-凝胶法制备TiO₂粉体,设计正交实验得到最佳配比条件为乙醇34mL,冰醋酸0.8mL,浓硝酸0.4mL,蒸馏水3mL。颗粒平均粒径在20-30nm之间,与沉淀法制备的TiO₂粉体相比具有:分散性好、粒度较细且均匀等特点。采用溶胶-凝胶法制备V⁵⁺、Ag⁺、Ni²⁺、Fe³⁺掺杂TiO₂纳米粉体,考察了掺杂量、煅烧温度、冰醋酸及浓硝酸加入量等因素的影响,得出了最佳工艺条件。以甲基橙为降解物研究了掺杂TiO₂的光催化降解性能,在自制光催化反应装置下光照1.5小时后测试甲基橙降解脱色率:V⁵⁺掺杂TiO₂纳米粉体降解率为73.43%,Ag⁺掺杂为79.38%,Ni²⁺掺杂为87.21%,Fe³⁺掺杂为78.11%。研究分析了纳米TiO₂粒径大小、煅烧温度和不同金属离子掺杂对锐钛矿型TiO₂拉曼图谱的影响。结果表明随着纳米TiO₂尺寸减小分别在143.1cm^-1Eg发生不同程度的谱峰蓝移,在396.0cm^-1B_1g处谱峰先发生红移到一定值后再蓝移,515.0B_1g和A_1g处发生较大程度的红移;随着煅烧温度的升高,在143.1cm^-1E_g、396.0cm^-1B_1g、637.7cm^-1E_g处发生不同程度的谱峰蓝移,515.0cm^-1B_1g和A_1g先红移到一定值再蓝移;离子掺杂时,导致纳米TiO₂粒径减小、峰强度降低、拉曼光谱产生较大宽化。本研究通过不同方式合成纳米TiO₂粉体,为制备纳米TiO₂的产业化提供了依据;并且通过掺杂金属离子提高纳米TiO₂的光催化降解性能,拓宽了纳米TiO₂的实际应用范围。更多还原

【Abstract】 In recent years,scientists have paied more attentions to the synthesized nanometer TiO₂ as a new photo catalyzer.It is wildly used for treating waste liquids,purifying air,killing bacteria and viruses,self-cleaning material as the low-cost,no poison,high stability.In this paper,the synthesized methods of nanometer TiO₂ were studied.The micro properties of nanometer TiO₂ powders were characterized by XRD,TEM,TG-DSC and Raman.The photocatalystic property of nanometer TiO₂ powders was improved by dropping with metal ions.Nanometer TiO₂ powders was synthesized by deposition method.The cation surfactant（CTAB）and anion surfactant（SDS,SDBS）was added to solve the nanoparticle agglomerates phenomenon.Nanometer TiO₂ powders were separated well using SDBS as surfactant.The average grain size is 32nm.The TiO₂ powder average size is 64nm using CTAB as surfactant and have agglomerates phenomenon.Nanometer TiO₂ powders was synthesized by Sol-Gel method.The mainly effects including ethanol,acetic acid,nitric acid, distilled water was analyzed.The best synthesized condition is ethanol 34mL,acetic acid 0.8mL,nitric acid 0.4mL,distilled water 3mL by orthogonal experiment.The average particle size is 20-30nm.Compare with deposition method,Nanometer TiO₂ powders were separated well,powder size was decreased.TiO₂ powder dropped with V⁵⁺、Ag⁺、Ni²⁺、Fe³⁺was prepared by Sol-Gel method.The quantity of metal ion,acetic acid,nitric acid and calcineing temperature was investigated to analyze the effect to synthesizing TiO₂.The best synthesized condition was obtained by orthogonal experiment with various metal ions.The photochemical capability of TiO₂ dropped with V⁵⁺、Ag⁺、Ni²⁺、Fe³⁺was studied by the degradation of methyl orange.The degradation of methyl orange was tested after 1.5h.The maximum ratio of TiO₂ dropped with V⁵⁺,Ag⁺,Ni²⁺and Fe³⁺can reach to 79.38%,79.38%,87.21%,78.31%.The TiO₂ powder size,heat treatment temperature and different dropped metal was take into consider in this article to illustrate the influence to the Raman spectrum of TiO₂.In 143.1cm^-1E_g,the spectrum of TiO₂ was blue shift as the decreasing of the TiO₂ powder size while in 515.0cm^-1B_1gand A_1gthe Raman spectrum was red shift.As the increasing of heat treatment temperature the Raman spectrum of TiO₂ was blue shift in 143.1cm^-1E_g,396.0cm^-1 B_1gand 637.7cm^-1E_g,it was blue shift after red shift in 515.0cm^-1B_1gand A_1g.The TiO₂ powder size was decreased dropped with metal ion and the Raman spectrum of TiO₂ intensity was reduced,the Raman spectrum of TiO₂ become wide.In this article,the nanometer TiO₂ powders were synthesized by different method.It provided some experience for the practical application.Also the various metal ions were dropped into TiO₂,the photochemical capability of TiO₂ was increased.更多还原