掺杂铁的二氧化钛薄膜的光催化性能的研究

【作者】 张景绘；

【导师】 孙力军；

【作者基本信息】 昆明理工大学 ， 材料学， 2005， 硕士

【摘要】 随着经济的快速增长,人们对环境也越来越重视。TiO₂作为一种环境友好型材料引起了很多学者的关注。 光催化氧化技术是一种新型的废水处理技术,具有处理效率高、工艺设备简单、操作条件易控制、非选择性的降解有机污染物、无二次污染等特点。光催化技术的诞生,开创了染料废水降解的新局面。在多种可作为光催化剂的半导体化合物中,二氧化钛因禁带能级较宽,具有强大的氧化能力,且化学性质稳定性好,催化活性高、抗磨损性好、价廉易得、无毒、自然界储藏丰富等特点,成为最常用的光催化剂。 本论文采用溶胶-凝胶法制备TiO₂薄膜,在掺杂铁元素后,研究其XRD性质及在紫外光照射下对甲基橙及亚甲基兰溶液的光催化降解效果。 烧结温度对TiO₂的晶型有一定的影响,在400℃和600℃烧结的二氧化钛的结晶程度明显好于烧结温度为200℃的二氧化钛的结晶程度,而烧结温度为400℃、600℃的二氧化钛的结晶衍射峰差别不大并且在同一烧结温度,随着保温时间的延长,锐钛矿型二氧化钛的结晶越来越好。 试验证明掺杂3%铁的二氧化钛薄膜能够有效很降解甲基橙及亚甲基兰溶液。试验结果表明:甲基橙溶液浓度为5mg/1时,其在pH=2时光照10h降解率达到97.44%;浓度为10mg/1时,其在pH=3时光照14h降解率达到97.96%;浓度为15mg/1时,其在pH=3时光照16h降解率达到98.24%;浓度为20mg/1时,其在pH=2和pH=3时光照16h降解率都达到了98.15%。浓度低的甲基橙溶液比浓度高的甲基橙溶液更容易光催化降解。 对浓度为10mg/1的亚甲基兰溶液的光催化降解试验表明:在pH=5时降解效果最好,其降解率达到99.52%。 本论文还初步探讨了TiO₂对选矿废水中黄药的降解机理。对黄药的处理引入了芬顿法进行预处理。试验结果表明掺杂3%铁的二氧化钛薄膜能有效光催化降解黄药,其降解率达到96.44%。更多还原

【Abstract】 With the development of economy, people now pay more attention to the environment. As a environmental material, the titanium dioxide has evokes more and more interest of researchers.. Photocatalytic degradation is a new technology of treating waste water with a high effencicy of treatment, simple equipment, easy-controlled, and without particular degration of pollutant ang secondary polluting etc. The naissance of the Photocatalytic degradation technology has blazed a new way in treating the waste water. Among a variety of semiconductor compounds which have catalyzing effect, the titanium dioxide becomes the most often used catalyst for its many advantages such as wide veto band, stronger oxidizing ability, and good chemical stability, high catalyzing power , good resist to wear away, low cost and availability , non - toxic, anundant in Nature.In this dissertation, the titanium dioxide films were prepared by sol-gel process. After doping Fe³⁺, the XRD features of TiO₂ have been investigated and the effect of photocatalytic degradation of the Methyl orange and Methylene Blue by TiO₂ have also determined.The sintering temperature has been found to affect the TiO₂’ s crystalization. At 400℃, 600℃, the crystal of titanium dioxide was better than that at temperature of 200℃. The anatase-typed crystal of TiO₂ getting pefect witj the heat preservation time.The results obtained indicate that doping of Fe³⁺ into TiO₂ film has a positive effect to the photocatalytic degradation. To Methyl orange, when the concentration is 5mg/l, the best condition is pH=2 under UV light for lOhs , the degradation reached 97.44%;when the concentration is 10mg/1, the best condition is pH=3 under UV light for 14hs , the degradation reached 97.96%;when the concentration is 15mg/l, the best condition is pH=3 under UV light for 16hs , the degradation reached 98.24%;when theconcentration is 20mg/l, the best condition is pH=2 and pH=3 under UV light for 16hs , the degradation reached 98. 15%. To Methylene Blue, when it’ s concentration is 10 mg/1, the best condition is pH=5, the degradation reached 99. 52%.In this dissertation, the degradation mechanism of xanthate with a combined use of the Fenton method. The results obtained TiOz film with doped Fe3+ has better effect to the photocatalytic degradation of xanthate and the degradation reached 96.44%.更多还原