氟氧化铋基复合材料的合成及性能研究

发布时间：2018-03-09 16:22

本文选题：复合材料　切入点：光催化　出处：《湘潭大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着工业的发展,全球环境污染越来越严峻。光催化、超声催化、染料分离因高效、绿色而引起了广泛的关注。铋基半导体作为一种重要的光催化材料,成为了光催化领域的研究热点。其中,卤氧化铋BiOX(X=Cl,Br,I)因其特殊的结构而在处理污染物方面表现出良好的催化性能。然而,关于将氟氧化铋(BiOF)用来处理有机污染物的研究很少,BiOF仍存在光催化活性较低等问题。本论文通过一些简单的方法合成了一系列BiOF基复合材料,以改善BiOF的性能。具体研究内容如下:(1)通过简单的一步溶剂热法制备了BiOF/Bi_2O_3复合材料。系统地研究了pH值对Bi OF/Bi_2O_3晶相、形貌、催化活性的影响。采用XRD、SEM、TEM、XPS、UV-Vis DRS对BiOF/Bi_2O_3进行了表征。结果表明,当pH调节为2-3或7-11时,所制备的产物为t-Bi OF/m-Bi_2O_3复合材料,由分布均匀的片状粒子组成。此外,我们通过对RhB的降解来评估不同样品的催化活性。当pH=2时,所制备的Bi OF/Bi_2O_3纳米片的的催化活性最高。同时,也对BiOF/Bi_2O_3(pH=2)进行了接触角测试,其薄膜经过硬脂酸修饰后具有超疏水性质(155.41o)。(2)通过简单的室温搅拌法首次制备了BiOF/Bi_2O_3/CaWO_4复合材料。系统地研究了搅拌时间、表面活性剂及CaWO_4的摩尔分数对Bi OF/Bi_2O_3/CaWO_4性质的影响。通过XRD、SEM、TEM、XPS、BET、TG、元素映射对BiOF/Bi_2O_3/CaWO_4进行了表征。结果表明,当搅拌时间为10 min,加入0.5 g十二烷基苯磺酸钠且x(CaWO_4)=85%时,所制得的Bi OF/Bi_2O_3/CaWO_4由CaWO_4微球和BiOF/Bi_2O_3纳米片组成,热稳定性优异,对亚甲基蓝的吸附性能最高,染料分离效果最好,可循环利用。此外,我们也对S_t-1进行了接触角测试。其薄膜在未修饰时也具有超疏水性质。(3)通过一步超声法制备了BiO_xF_y/BiVO_4复合材料。通过XRD、SEM和XPS等测试对BiO_xF_y/Bi VO4进行了表征。并研究了超声时间、表面活性剂对Bi OxFy/BiVO_4催化活性的影响。结果表明,不同超声时间下制得的产物均为Bi VO4/BiO_(0.51)F_(1.98)复合物,超声时间越长,BiVO_4/BiO_(0.51)F_(1.98)对亚甲基蓝的催化活性越高。表面活性剂对产物的性质有一定的影响。当加入1 g十二烷基苯磺酸钠时,制得的Bi O0.67F1.66/BiVO_4的催化性能最高。
[Abstract]:With the development of industry, global environmental pollution is becoming more and more serious. Photocatalysis, ultrasonic catalysis and dye separation have attracted wide attention because of their high efficiency and green. Bismuth based semiconductor is an important photocatalytic material. Bismuth bismuth halide (BiOXO _ XO _ 2) has shown good catalytic performance in the treatment of pollutants due to its special structure. In this paper, a series of BiOF matrix composites were synthesized by some simple methods, such as the low photocatalytic activity of BiOF. In order to improve the properties of BiOF, BiOF/Bi_2O_3 composites were prepared by a simple one-step solvothermal method. The effects of pH value on the crystal phase and morphology of BiOF/Bi_2O_3 were systematically studied. The effect of catalytic activity on the catalytic activity. The BiOF/Bi_2O_3 was characterized by XRDD-SEMTEMN UV-Vis DRS. The results showed that when pH was adjusted to 2-3 or 7-11, the synthesized product was t-Bi OF/m-Bi_2O_3 composite, which was composed of uniformly distributed flake particles. The catalytic activity of different samples was evaluated by the degradation of RhB. When pH = 2:00, the catalytic activity of the prepared BiOF/Bi_2O_3 nanoparticles was the highest. The BiOF/Bi_2O_3/CaWO_4 composite was prepared by simple room temperature stirring method, and the stirring time was studied systematically, and the film was modified with stearic acid and had superhydrophobic properties. The effect of the molar fraction of surfactant and CaWO_4 on the properties of BiOF/Bi_2O_3/CaWO_4 was studied. The elemental mapping was used to characterize the properties of BiOF/Bi_2O_3/CaWO_4. The results showed that when the stirring time was 10 min, 0.5 g sodium alkylbenzenesulfonate was added, the content of BiOF/Bi_2O_3/CaWO_4 was 85g. The prepared BiOF/Bi_2O_3 / CaWOS _ 4 is composed of CaWO_4 microspheres and BiOF/Bi_2O_3 nanoparticles, has excellent thermal stability, has the highest adsorption performance for methylene blue, and has the best dye separation efficiency and can be recycled. We also tested the contact angle of St-1. The thin film was also superhydrophobic when unmodified. (3) the BiO_xF_y/BiVO_4 composite was prepared by one-step ultrasonic method. The BiO_xF_y/Bi VO4 was characterized by XRD-SEM and XPS. The ultrasonic time was also studied. The effect of surfactants on the catalytic activity of Bi OxFy/BiVO_4 was studied. The longer the ultrasonic time is, the higher the catalytic activity for methylene blue is. The surfactant has a certain influence on the properties of the product. When 1 g sodium alkylbenzene sulfonate is added, the catalytic activity of BiO0.67F1.66 / BiVOS4 is the highest.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332;O643.36

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