【作者】 陈娜娜；

【导师】 吴玉程；

【作者基本信息】 合肥工业大学 ， 材料学， 2010， 硕士

【摘要】 纳米TiO2是一种高活性的催化剂,在净化空气、处理污水等方面具有重要的应用价值。本文针对纳米TiO2粉体的光吸收仅限于紫外光区、量子产量低等不足,采用溶胶-凝胶法,以过渡金属元素、稀土元素单掺杂以及非金属元素和金属元素双掺杂来改善纳米TiO2的性质。针对纳米TiO2粉体分散到水介质中会产生催化剂难以回收再利用的问题,本文采用电化学的方法实现了与Ni-P基质共沉积,制备纳米TiO2复合涂层。利用X射线衍射、扫描电镜及电子能谱等方法表征了改性纳米粉体以及纳米复合涂层的组织结构、表面形貌和成分,研究了复合涂层的显微硬度并评价了改性纳米粉体和复合涂层的光催化性能。采用溶胶-凝胶法制备Ce-TiO2、Co-TiO2和Zn-TiO2粉体。通过改变热处理温度来控制改性纳米TiO2粉体的相变过程,可获得粒径小、纯度高的一元掺杂纳米TiO2光催化剂。改性TiO2的最佳的热处理温度为500℃。三种元素的最佳掺杂浓度分别为0.6%、0.5%、0.8%,其最佳光催化降解率分别为67%、75%、62%。在采用溶胶‐凝胶法制备Ce-TiO2、Co-TiO2和Zn-TiO2光催化剂的基础上,对三种粉末进行渗氮处理。N的掺杂提高了TiO2的光催化活性,三种粉末对甲基橙的降解率分别达到83%、94%、76%。Ni-Co-P-纳米TiO2复合涂层的电沉积液最佳配方为:TiO2为6g/L,施镀温度为60℃,表面活性剂为200mg/L,搅拌速度为200r/min,电流密度为5A/dm2,在最佳工艺配方条件下制备的复合涂层中纳米TiO2的复合量达到7.53%;在最佳工艺条件下制备的Ni-Co-P-纳米TiO2复合涂层的光催化性能与纳米TiO2粉体的光催化性能大致相近,略低于粉体的光催化性能。更多还原

【Abstract】 Nano-TiO2 materials have great application values in wastewater treatment and air purification because of its high photocatalytic properties. Light absorption of nano-TiO2 powder is only limited in UV and nano-TiO2 has lower quantum yield. In this paper, rare-earth element or transistion metal element mono-doped nano-TiO2 and nonmetal element and metal element coped nano-TiO2 was prepaered to improve the properties of nano-TiO2 using sol-gel method. Catalyst is difficult to recovery and reuse when Nano-TiO2 powder were dispersed in water medium. To settle this problem, the nano-TiO2 particles were introduced into plating bath based on plating Ni-Co-P to make the nano-TiO2 particles and Ni、Co、P matrix co-deposit to obtain nano-TiO2 composite coatings. Microstructure, morphology and composition of doped nano-TiO2 and composite coatings were characterized by XRD, SEM and EDS techniques. The Micro-hardness of composite coatings was investigated as well as photocatalytic performance of doped nano-TiO2 and nano-TiO2 composite coatings.Ce-TiO2、Co-TiO2 and Zn-TiO2 powder was prepared by sol-gel method. The particle size and phase transformation process of one-element doped nano-TiO2 can be controlled by changing heat-treating temperature the one-element doped nano-TiO2 with small size and high purity were obtained. The result showed that temperature(500℃) was the best heat treatment temperature of the nano-TiO2 and the optimal concentration of the doping agent were 0.6, 0.5 and 0.8 % respectively. Correspondingly, photocatalytic decomposing rate of methyl orange solution were 67, 75 and 62% respectively.On the base of prepared Ce-TiO2, Co-TiO2 and Zn-TiO2 by sol-gel method, three kinds of powder were subjected to nitriding treatment. Doping nitrogen can improve the photocatalytic activities of TiO2. Their photocatalytic decomposing rate of methyl orange solution were up to 83, 94 and 76% respectively.The optimum process of electro-deposition of Ni-Co-P-nano-TiO2 composite coating is achieved: TiO2 content is 6g/L, bath temperature 60℃,surfactant content 200mg/L , stir speed 200r/min and current density 5A/dm2. The content of nano-TiO2 in the composite coating is up to 7.53%. The photocatalytic performance of Ni-Co-P-nano-TiO2 composite coating is slightly lower than nano-TiO2 powder.更多还原