含铋配位聚合物的制备、改性及其光催化性能研究

发布时间：2018-08-08 17:42

【摘要】：光催化技术作为一项具有重要应用前景的绿色技术,被广泛用于处理印染废水。目前,配位聚合物凭借其种类多样、结构可控、热稳定性高及比表面积大等优点广泛应用于光催化领域研究。此外,铋系氧化物由于具有较窄的禁带宽度而成为极具发展前景的可见光响应光催化剂。近年来,石墨烯作为一种具有优异导电性能和吸附性能的新材料,常被用来与其他材料制备成复合物,其复合物通常具有更好的光催化性能,使光催化技术得到快速发展。鉴于含铋配位聚合物极少报道,且并未对其光催化性能进行过深入的探讨,本文将针对这些问题展开研究。具体内容如下:首先,通过水热法合成一种新型二维结构钴铋双金属配位聚合物(简称:24pCoBi),其分子式为BiCoC_(21)H_(17)N_3O_(16)。对24pCoBi进行高温煅烧得到一复合物(简称:24pCoBi500)。分别对两种材料进行多种表征,并通过计算得到材料的禁带宽度近似值。在模拟太阳光下,两种材料降解亚甲基蓝(MB)的能力强弱顺序为:24pCoBi50024pCoBi;可见光下降解罗丹明B(RhB)的能力强弱顺序为:24pCoBi24pCoBi500。设计实验改变RhB溶液的pH得出结论:24pCoBi在强酸条件下对RhB的降解效果最佳,强碱条件下(pH12.40)则发生变性。其次,用水热法合成了一种已知结构的铜铋双金属配位聚合物(简称:35pCuBi)并对其进行高温煅烧得到一种复合物(简称:35pCuBi500),同时用水热法合成了铜铋双金属配位聚合物与石墨烯的复合物(简称:35pCuBi/Gr)。分别对三种材料进行多种表征,并通过计算得到材料的禁带宽度近似值。通过在模拟太阳光下降解MB、可见光下降解RhB考察了三种材料的光催化性能强弱顺序为:35pCuBi50035pCuBi/Gr35pCuBi。设计实验改变RhB溶液的pH得出结论:35pCuBi在强酸条件下对RhB的降解效果明显提升,其较适宜反应pH为1.82。最后,探讨了35pCuBi/Gr的光催化反应机理。在35pCuBi/Gr的结构中,石墨烯优良的导电性能可以加快光生电子的转移速度,从而降低光生电子空穴对的复合率、提高太阳光利用率。同时石墨烯的强吸附作用可使有机分子与光催化剂充分接触,加速光催化反应的进行。实验结果显示,可见光下35pCuBi/Gr对pH 1.82的RhB溶液的两次循环降解中,其降解率均可在10分钟内达到97%以上,且材料结构不发生改变。
[Abstract]:As a green technology with important application prospect, photocatalytic technology is widely used in the treatment of printing and dyeing wastewater. At present, coordination polymers are widely used in the field of photocatalysis due to their various types, controllable structure, high thermal stability and large specific surface area. In addition, bismuth oxide is a promising photocatalyst for visible light response due to its narrow band gap. In recent years, graphene, as a new material with excellent conductivity and adsorption properties, is often used to prepare composites with other materials. The complexes usually have better photocatalytic properties, which make the photocatalytic technology develop rapidly. Since the coordination polymers containing bismuth are rarely reported and their photocatalytic properties have not been thoroughly discussed, these problems will be studied in this paper. The main contents are as follows: firstly, a novel two-dimensional cobalt-bismuth bimetallic coordination polymer was synthesized by hydrothermal method. Its molecular formula is BiCoC21 H17 N3O16. 24pCoBi was calcined at high temperature to obtain a complex (: 24pCoBi500). Two kinds of materials were characterized and the approximate band gap of the materials was obtained by calculation. Under simulated solar light, the degradation ability of methylene blue (MB) was in the order of: 24pCoBi50024pCoBiand that of visible light descending solution of Rhodamine B (RhB) was: 24pCoBi24pCoBi500. By changing the pH of RhB solution, it is concluded that the degradation effect of RhB is the best under strong acid condition, and denaturation occurs in strong base condition (pH12.40). Secondly, A copper-bismuth bimetallic coordination polymer with known structure (: 35pCuBi) was synthesized by hydrothermal method and calcined at high temperature to obtain a complex (w / 35pCuBi500). At the same time, copper-bismuth bimetallic coordination polymer and graphite were synthesized by hydrothermal method. A complex of alkenes (called: 35 pCuBir / Gr). The three kinds of materials were characterized in different ways, and the approximate band gap of the materials was obtained by calculation. The photocatalytic properties of the three materials were investigated in the order of: 35pCuBi50035pCuBi-Gr35pCuBiR / Gr35pCuBiR by degradation of MBB in simulated solar light and degradation of RhB under visible light in the order of: 35pCuBi50035pCuBi-Gr35pCuBi. The pH of RhB solution was changed by designing experiments. It was concluded that the degradation effect of RhB was obviously improved under the condition of strong acid, and the optimum reaction pH was 1.82. Finally, the photocatalytic reaction mechanism of 35pCuBi/Gr was discussed. In the structure of 35pCuBi/Gr, the excellent conductivity of graphene can accelerate the transfer rate of photogenerated electrons, thus reducing the recombination rate of photogenerated electron hole pairs and increasing the utilization ratio of sunlight. At the same time, the strong adsorption of graphene can make organic molecules fully contact with photocatalyst and accelerate the photocatalytic reaction. The experimental results show that the degradation rate of RhB solution with pH 1.82 can reach more than 97% in 10 minutes after two cycles of 35pCuBi/Gr degradation under visible light, and the structure of the material does not change.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.4

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