不同形貌的二氧化钛微球的制备及光催化性能的研究

发布时间：2018-12-20 06:16

【摘要】：由于二氧化钛在太阳能转化,光催化,净水,锂离子电池阳极等多方面的应用,受到了科学家们的广泛关注。为了满足不同的应用需求,制备合成不同形貌,尺寸及相组成的TiO2纳米材料是十分必要的。通常制备合成满足上述条件的TiO2纳米材料,需要多步反应或较高的实验条件,很少一步制得。本论文采用低温下一步溶剂热法合成了TiO2纳米微球,通过对实验条件一系列的调整合成出多种形貌的TiO2纳米材料,晶型组成为金红石型和锐钛矿/金红石混晶两种晶型。主要的形貌组成有：一维纳米线,簇状微球,海胆型微球,花状微球。并采用XRD, SEM, DSC 和TG对其结构、形貌以及性能进行表征,同时进行了光催化性能的测试。在此基础上,分别通过加入Sn2+和Zn2+离子对Ti02进行离子掺杂修饰制备了掺杂二氧化钛微球；并采用XRD, SEM, TEM, XPS, BET, DSC和TG对其结构、形貌以及性能进行表征,通过对试样的反应物种类组成,比例组成,以及实验条件等众多条件进行调节,探索出最适宜的反应条件,并成功制备出多种形貌的TiO2纳米材料,同时也进行了光催化测试。主要的研究结果如下：1.采用低温下一步溶剂热法合成了TiO2微球,并且对其结构,形貌,热稳定性,以及光催化性能进行了表征,结果表明：在黑暗条件0.5 h达到吸附平衡后,总吸附量为5%,在紫外灯照射下,光催化降解1.5 h后,降解量为40%。2.在上述工作的基础上,对TiO2微球进行了金属阳离子修饰。当掺杂修饰离子为Sn2+时,通过对实验中反应物的组成,反应的实验条件等进行调节,可以成功制备出不同尺寸的海胆微球,此时的相组成为金红石型TiO2,在黑暗条件0.5 h达到吸附平衡后,总吸附量为5%,在紫外灯照射下,光催化降解1.5 h后,降解量为90%。当对实验中反应物的比例进行调解时,可以成功制备出对比鲜明的各种形貌的TiO2纳米结构,在紫外光下,对甲基橙进行光催化降解实验,发现当相组成为锐钛矿/金红石混晶时,具有最好的光催化性能。在黑暗条件0.5 h达到吸附平衡后,总吸附量为8%,在紫外灯照射下,光催化降解5 min后,降解量为98%。主要的影响归结于晶型的组成,以及比较大的比表面积。3.修饰离子为Zn2+时,对时间,温度,盐酸,Zn2+盐的阴离子,缓释剂等多个实验条件的影响进行了研究,制备出了不同形貌的Zn2+掺杂Ti02微球。在黑暗条件0.5 h达到吸附平衡后,总吸附量为10%,在紫外灯照射下,光催化降解60 min后,降解量为90%。实验研究了不同离子掺杂对材料形貌以及性能的影响,可知金属离子的修饰对TiO2微球形貌影响主要表现在微球表面刺状结构的不同,光催化性能测试表明,Sn2+掺杂的微球光催化性能最优异。上述的研究内容,将为未来进一步制备出更符合要求的TiO2纳米材料提供必要的实验基础和理论依据。
[Abstract]:Because of the application of titanium dioxide in solar energy conversion, photocatalysis, water purification, anode of lithium ion battery and so on, scientists have paid more and more attention to it. In order to meet different application requirements, it is necessary to synthesize TiO2 nanomaterials with different morphologies, sizes and phases. Usually, the synthesis of TiO2 nanomaterials satisfying the above conditions requires multi-step reaction or higher experimental conditions, but rarely in one step. In this paper, TiO2 nanocrystalline was synthesized by next step solvothermal method at low temperature. By adjusting the experimental conditions, a series of morphologies of TiO2 nanocrystals were synthesized. The crystal forms of TiO2 nanocrystals were rutile and anatase / rutile mixed crystal. The main morphologies are as follows: one-dimensional nanowire, cluster-shaped microspheres, sea urchin-shaped microspheres and flower-like microspheres. The structure, morphology and properties were characterized by XRD, SEM, DSC and TG, and the photocatalytic properties were tested. On this basis, doped TIO _ 2 microspheres were prepared by adding Sn2 and Zn2 ions to Ti02. The structure, morphology and properties of the samples were characterized by XRD, SEM, TEM, XPS, BET, DSC and TG. The composition of the reactants, the proportion of the reactants and the experimental conditions were adjusted. The most suitable reaction conditions were explored, and various morphologies of TiO2 nanomaterials were successfully prepared, and photocatalytic tests were also carried out. The main results are as follows: 1. The structure, morphology, thermal stability and photocatalytic properties of TiO2 microspheres were characterized by the next step solvothermal method at low temperature. The results showed that the total adsorption capacity was 5g after the adsorption equilibrium reached 0.5 h in dark conditions. Under the irradiation of ultraviolet lamp, the photocatalytic degradation rate was 40. 2 after 1.5 h photocatalytic degradation. On the basis of the above work, TiO2 microspheres were modified with metal cations. When the doped modified ion is Sn2, the different sizes of sea urchin microspheres can be successfully prepared by adjusting the composition of reactants and the experimental conditions of the reaction, and the phase composition is rutile type TiO2,. When the adsorption equilibrium was reached at 0.5 h in the dark condition, the total adsorption capacity was 5. Under ultraviolet lamp irradiation, the photocatalytic degradation was 1.5 hours later, the degradation amount was 90%. When adjusting the proportion of reactants in the experiment, the TiO2 nanostructures with different morphologies can be prepared successfully. The photocatalytic degradation of methyl orange can be carried out under ultraviolet light. It is found that when the phase composition is anatase / rutile mixed crystal, it has the best photocatalytic performance. When the adsorption equilibrium was reached at 0. 5 h in dark condition, the total adsorption capacity was 8. Under ultraviolet lamp irradiation, the photocatalytic degradation rate was 98% after 5 min photocatalytic degradation. The main effect is attributed to the composition of crystal form and larger specific surface area. 3. 3. When the modified ion is Zn2, the effects of time, temperature, anion of hydrochloric acid, Zn2 salt and slow release agent on the experimental conditions were studied. Zn2 doped Ti02 microspheres with different morphologies were prepared. When the adsorption equilibrium was reached at 0.5 h in dark conditions, the total adsorption capacity was 10. Under ultraviolet lamp irradiation, the photocatalytic degradation was 90% after 60 min photocatalytic degradation. The effects of different ion doping on the morphology and properties of TiO2 microspheres were studied. The results show that the effect of metal ions modification on the morphology of TiO2 microspheres is mainly due to the different spiny structure on the surface of the microspheres. Sn2 doped microspheres have the best photocatalytic performance. The above research contents will provide the necessary experimental and theoretical basis for the further preparation of more suitable TiO2 nanomaterials in the future.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O614.411;TB383.1

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