【作者】 朱曜峰；

【导师】 傅雅琴；

【作者基本信息】 浙江理工大学 ， 材料加工工程， 2010， 硕士

【摘要】 二氧化钛的负载化和催化活性的进一步提高,是扩大光催化材料实用化范围的关键所在。本论文选用聚丙烯腈基碳纤维（PAN-CF）为载体,探索合适的溶胶凝胶工艺,通过浸渍涂覆技术制备碳纤维负载二氧化钛薄膜光催化复合材料,并重点研究TiO₂薄膜结构及改性对碳纤维负载TiO₂复相光催化材料催化性能的影响。首先,以Ti（OC₄H₉）₄-C₂H₅OH-H₂O体系的全相图为理论依据,采用不同的溶胶体系及热处理工艺制备不同的TiO₂/CF光催化材料,并对材料结构与性能进行表征,结果表明:溶胶浓度影响制备材料的形态结构、CF对TiO₂的负载率及负载牢度;溶胶的浓度和退火温度对制备材料的催化活性有明显的影响。Ti浓度为0.5M的溶胶制备的TiO₂/CF负载牢度好,负载率高,催化活性好。另外,考虑碳纤维的热稳定性,以退火温度为600℃下保温2h,升温速率为2³℃/min,为最佳的热处理工艺。其次,为了充分利用载体的吸附性能,以提高TiO₂/CF光催化材料的催化活性,以聚乙二醇（PEG）为模板剂改性钛溶胶,制备了多孔TiO₂/CF光催化材料,研究了多孔TiO₂/CF光催化复合材料对甲基橙溶液及品红溶液的吸附性能,以及复合材料对甲基橙溶液的光催化性能,结果表明:多孔TiO₂/CF光催化材料对甲基橙染料及品红染料的吸附符合准二级动力学方程,且吸附量随PEG分子量的增大而增加;PEG分子量为2000时,与TiO₂/CF相比,对甲基橙溶液的光催化效率有了一定的提高。再次,采用溶胶凝胶法及浸渍涂覆技术分别制备了碳纤维负载TiO₂/SnO₂双层结构薄膜光催化材料（TiO₂/SnO₂ /CF）及碳纤维负载SnO₂-TiO₂混合型薄膜光催化材料（SnO₂ -TiO₂/CF）。结果表明:TiO₂/SnO₂双层薄膜有效提高了材料的催化活性,与TiO₂/CF相比,TiO₂/SnO₂ /CF对甲基橙溶液的光催化降解效率提高了13.3%;而对于混合型的SnO₂-TiO₂/CF,当SnO₂含量为20%时,SnO₂ -TiO₂/CF比TiO₂/CF催化活性有了明显提高,对酸性橙Ⅱ溶液催化降解效率提高了近60%。最后,提出了通过简单的氧化还原技术,对载体表面进行贵金属Pd修饰的方法,提高碳纤维负载二氧化钛光催化的材料（TiO₂/ Pd-CF）的催化性能,结果表明TiO₂/ Pd-CF催化活性比TiO₂/CF有很大的提高,且当Pd粒子的沉积量为10.8mg/g时,对酸性橙Ⅱ溶液催化效果提高了70%以上,为提高负载型光催化材料提供了新思路。更多还原

【Abstract】 Preparation of immobilized photocatalytic titanium dioxide materials and further improvement of the photocatalytic activity of the materials are keys to expand the scope of practical application of photocatalytic materials. In this paper, the composite photocatalyst of TiO₂ thin film supported on polyacrylonitile based carbon fiber （PAN-CF） substrates was prepared by sol-gel dip coating technique and a suitable sol-gel process was explored. The effects of the TiO₂ thin film structure and its modification on the photocatalytic performance of the composite photocatalyst of TiO₂ thin film supported on carbon fiber materials were researched.First, the TiO₂/CF photocatalyst materials were prepared by different sol systems and heat treatment processes on the basis of the multicomponent system phase diagram theory of Ti（OC₄H₉）₄-C₂H₅OH-H₂O, and the structures and properties of the materials were studied. The results suggest that the concentration of the sol has significant effects on the morphologies and structures of TiO₂/CF film, the load rate of TiO₂ and load fastness. It also indicated that the catalytic activity of TiO₂/CF film is remarkably influenced by the concentration of the sol and annealing temperature, and the TiO₂/CF prepared from the Ti sol with concentration of 0.5M exhibits better load fastness, higher load rate and excellent catalytic performance. Moreover, The optimum heat treatment process was determined as annealed at 600℃for 2 hours at a rate of 2³℃/min.Second, in order to make full use of the adsorption properties of carrier, the TiO₂ porous film photocatalysts deposited on carbon fiber were fabricated through the sol-gel dip-coating technology using PEG-modified titanium sol. The adsorption effects of the composites to methyl orange and fuchsin, and the photocatalytic property of the composites to methyl orange were investigated respectively. The results suggest that the adsorption kinetic process of TiO₂/CF composites to methyl orange solution and fuchsin fitted very well with the pseudo-second-order kinetic model. In addition, with the improvement of PEG molecules, the adsorption capacity is increased, and the catalytic performance of porous TiO₂/CF using PEG2000 as a template was increased on some degree that compare with TiO₂/CF by photocatalytic degradation of methyl orange solution.And then, the compound photocatalysis material of TiO₂/SnO₂ films with bilayer structure （TiO₂/SnO₂/CF） and TiO₂-SnO₂ hybrid films supported on carbon fiber（SnO₂-TiO₂/CF） were prepared by sol-gel dip-coating technology, respectively. The study revealed that the photocatalytic activity of the composite is efficiently enhanced by using TiO₂/SnO₂ films with bilayer structure, and the photocatalytic degradation efficiency of TiO₂/SnO₂/CF was improved 13% compare with TiO₂/CF, by photocatalytic degradation of methyl orange solution. The photocatalytic activity of SnO₂-TiO₂/CF with SnO₂ content of 20%（mole fraction） was markedly improved compare with TiO₂/CF, and the degradation efficiency of TiO₂/SnO₂/CF was improved 60% by photocatalytic degradation of acid orangeⅡsolution.The last, photocatalytic property of the TiO₂ films photocatalysts supported on Pd modified carbon fiber（TiO₂/ Pd-CF） was improved by the method of noble metal Pd modified carrier surface through a facile oxidation-reduction technology. The results indicate that the catalytic activity of TiO₂/Pd-CF exhibited greatly enhanced compare with TiO₂/CF, and the photocatalytic performance of TiO₂/Pd-CF towards the degradation of acid orangeⅡwas improved 70% when the Pd particles loading is 10.8mg/g. It provides a new idea for improving photocatalytic property of immobilized photocatalytic materials.更多还原