氨基化金属-有机骨架薄膜光催化降解有机污染物性能研究

Amine-functionalized metal-organic framework (MOF) thin films, with uneven surface and open network morphology, were prepared with related amine-ligands using electrochemical synthesis, to achieve high-efficient utilization of solar energy via their response wavelength red-shifting from UV light region to visible light region. In this proposal, the influence factors and corresponding control measures of thin film preparation will be investigated. The structure, morphology, element and properties of the as-prepared thin films will be characterized. The influence of the types and the initial concentrations of the selected organic pollutants, initial pH of the solution, added oxidants and their concentration and co-existing ions on the photocatalytic efficiency will be studied, along with the corresponding photocatalytic degradation mechanism, reaction pathway and kinetic behavior. We will also test the stability and repeatability of the as-prepared thin film, as well as determining their advantages and disadvantages via comparing with traditional photocatalyst thin film. The research MOFs as novel photocatalysts to achieve effective degradation of organic pollutants opens a new prospective and a feasible strategy for the wastewater treatment. To our best knowledge, few attentions were paid on the preparation of MOF thin film aiming to conduct photocatalytic degradation of organic pollutants. Our research group harvest much on the synthesis and application of MOF as photocatalyst, and recently, we had successfully prepared ZIF-8 thin film following the strategy stated in this proposal to achieve high efficiency degradation of organic pollutants. In all, from the scientific aspect, our achievements expected in this proposal will provide theoretical information on MOF thin film as photocatalyst to treat wastewater. And, the application of MOF thin film can avoid the difficulty of post-separation of powder photocatalysts, which spurs our research results possess prospective application.

采用电化学生长法制备由较大晶粒组成、表面起伏大、呈开放式网状形貌的氨基化金属-有机骨架（MOFs）薄膜，使其显示光催化性能的响应波长延长至可见光区，从而有效利用太阳能。探明影响薄膜制备的因素及调控措施，从结构、形貌、成分及性能方面对薄膜进行表征；研究目标降解物特性及初始浓度、pH、协同氧化剂种类和用量、共存离子等对降解效果的影响；探明该类薄膜光催化降解有机污染物的反应机理、途径及动力学行为；验证薄膜稳定性和可重复利用性，比较其与传统光催化剂薄膜光催化降解性能的优劣。MOFs作为光催化剂处理有机污染物在国内外均处起步阶段，制备该类薄膜更是鲜有先例。本课题组在合成具光催化性能的MOFs方面具备多年工作基础，已按申请书思路制备出该类薄膜并成功降解有机污染物，证明方法可行。本项目为批量制备氨基化MOFs薄膜处理含有机污染物的废水提供研究基础并解决粉体催化剂回用难之难题，具重要科学意义和实用价值。

为解决粉体MOFs催化剂使用后分离难、循环利用难等难题，本研究内容集中于制备不同种类的MOFs薄膜并用于批量处理含有机污染物废水提供基础研究。本研究采用电化学原位生长法、二次晶种法、聚多巴胺胶水法制备由较大晶粒组成、表面起伏大、呈开放式网状形貌的氨基化金属-有机骨架（MOFs）薄膜，使其显示光催化性能的响应波长延长至可见光区，从而有效利用太阳能。基本探明了影响薄膜制备的因素及调控措施，从结构、形貌、成分及性能方面对薄膜进行表征；研究了目标降解物特性及初始浓度、pH、协同氧化剂种类和用量、共存离子等对降解效果的影响；探明该类薄膜光催化降解有机污染物的反应机理、途径及动力学行为；验证薄膜稳定性和可重复利用性，比较其与传统光催化剂薄膜光催化降解性能的优劣。结果表明，薄膜形式能有效提高MOFs的水稳定性、光吸收效率，从而获得较高的光催化效率。MOFs薄膜不仅能光催化降解有机污染物，还能光催化还原Cr(VI)，且能经受还原六价铬所需的强酸环境。MOFs薄膜光催化剂有效解决了粉体催化剂回收难、循环利用难的困境，可以持续使用，且保持高效率。MOFs作为光催化剂处理有机污染物在国内外均处起步阶段。总之，本项目为批量制备MOFs薄膜（UiO-66-NH2(Zr)、UiO-66-NH2(Hf)、ZIF-8、ZIF-67等）处理含有机污染物的废水提供研究基础并解决粉体催化剂回用难之难题，具重要科学意义和实用价值。