ZnTe和ZnSe纳米材料的制备与性能研究

发布时间：2018-05-29 02:36

本文选题：溶剂热法 + 纳米复合物　；参考：《新疆大学》2017年硕士论文

【摘要】：碲化锌(ZnTe)和硒化锌(ZnSe)作为半导体光催化剂降解有机污染物在清洁能源领域具有巨大的应用前景。因其宽的禁带宽度、低的紫外光利用率和快的电子/空穴符合率,使其在光催化方面的应用受到了极大的限制。众多研究者通过各种有效的手段来解决这一系列问题,如:复合、掺杂、表面改性,均有效的克服了以上缺陷,同时大大提高了产物的光催化活性。本文利用简单有效的溶剂热法制备不同催化性能的ZnTe和ZnSe纳米材料,并对其进行了一系列的性能测试,主要研究内容如下:一.以ZnO作为Zn源,利用简单的溶剂热法成功合成ZnO/ZnTe/Te纳米复合物。通过改变二亚乙基四胺(DETA)的浓度,利用DETA的诱导成核和自组装作用可有效地控制产物形貌,并对产物光催化活性起到决定性的作用。此结果揭示DETA在控制产物形貌和光催化活性方面扮演着重要的角色。此外,在这个体系中N2H4配体具有双重效应包括:(1)充当纳米棒结构的插间分子,(2)充当分子模板指导产物形貌。在ZnO和ZnTe纳米材料的协同作用下,纳米复合物具有强的紫外可见光降解能力和低的电子/空穴复合速率。ZnO/ZnTe/Te纳米复合物展现强的紫外可见光驱动的光催化活性,在300W的汞灯照射2小时,50mg催化剂降解50ml亚甲基蓝(10mg/L)可达99.8%。二.通过溶剂热法,以乙酸锌和亚硒酸钠分别做锌源和硒源,氢氧化钠做还原剂,乙二胺四乙酸(EDTA)做螯合剂,水作为溶液制备的两相(立方相和六方相)共存的ZnSe纳米颗粒展现出高的光催化性能,在350W的氙灯照射2小时,20mg催化剂降解40ml亚甲基橙(40mg/L)可达84.4%。三.首先,利用水热法制备ZnO纳米棒,然后以ZnO纳米棒作为前躯体,加入一定量的乙酸铜利用化学沉浴法制备CuO/ZnO纳米复合物。通过一系列的表征手段表明CuO与ZnO复合具有高光催化活性,在300W的汞光照射2小时下,25mg催化剂降解25ml亚甲基蓝(15mg/L)可达99.7%。
[Abstract]:Zinc Telluride (ZnTe) and zinc selenide (ZnSee) have great application prospects in clean energy field as semiconductor photocatalysts for the degradation of organic pollutants. Because of its wide band gap, low UV utilization and fast electron / hole coincidence, its application in photocatalysis is greatly limited. Many researchers solve these problems by various effective methods, such as compound, doping, surface modification, effectively overcome the above defects, and greatly improve the photocatalytic activity of the product. In this paper, ZnTe and ZnSe nanomaterials with different catalytic properties were prepared by a simple and effective solvothermal method, and a series of performance tests were carried out. The main research contents are as follows: 1. Using ZnO as Zn source, ZnO/ZnTe/Te nanocomposites were successfully synthesized by a simple solvothermal method. By changing the concentration of diethylenetetramine (DETA), the nucleation and self-assembly induced by DETA can effectively control the morphology of the product and play a decisive role in the photocatalytic activity of the product. The results show that DETA plays an important role in controlling the morphology and photocatalytic activity of the product. In addition, the dual effects of N2H4 ligands in this system include: 1) acting as an intercalated molecule with nanorod structure and 2) acting as a molecular template to guide the morphology of the product. Under the synergistic action of ZnO and ZnTe nanocomposites, the nanocomposites have strong UV / visible photodegradation ability and low electron / hole recombination rate. ZnO / ZnTe- / Te nanocomposites exhibit strong photocatalytic activity driven by UV-Vis light. Under 300W mercury lamp irradiation for 2 hours with 50mg catalyst, the degradation of 50ml methylene blue (10mg / L) can reach 99.8mg / L. II. By solvothermal method, zinc acetate and sodium selenite were used as zinc and selenium source, sodium hydroxide as reducing agent and EDTA as chelating agent respectively. The two-phase (cubic phase and hexagonal phase) ZnSe nanoparticles prepared by water as solution exhibit high photocatalytic properties. The degradation of 40ml by 20mg catalyst (40 mg 路L ~ (-1) after irradiation of 350W xenon lamp for 2 hours can reach 84.4 g 路L ~ (-1). III. Firstly, ZnO nanorods were prepared by hydrothermal method, and then ZnO nanorods were used as precursors and a certain amount of copper acetate was added to prepare CuO/ZnO nanorods by chemical sedimentation bath. A series of characterization methods showed that CuO and ZnO had high photocatalytic activity. Under the irradiation of 300W mercury for 2 hours, the degradation of 25ml methylene blue by 25 mg catalyst (15mg / L) could reach 99.7%.
【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

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