催化学报 ›› 2015, Vol. 36 ›› Issue (12): 2071-2088.DOI: 10.1016/S1872-2067(15)60984-6

• 综述 • 上一篇    下一篇

MOFs光催化材料的设计和调控

沈丽娟a,c, 梁若雯a, 吴棱a,b   

  1. a 福州大学能源与环境光催化国家重点实验室, 福建福州 350002;
    b 中国科学院福建物质结构研究所结构化学国家重点实验室, 福建福州 350002;
    c 福州大学化肥催化剂国家工程研究中心, 福建福州 350002
  • 收稿日期:2015-08-29 修回日期:2015-09-24 出版日期:2015-12-02 发布日期:2015-12-07
  • 通讯作者: 吴棱
  • 基金资助:

    国家自然科学基金(21273036, 21177024); 国家重点基础研究发展计划(973计划)资助项目(2014CB239303).

Strategies for engineering metal-organic frameworks as efficient photocatalysts

Lijuan Shena,c, Ruowen Lianga, Ling Wua,b   

  1. a State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350002, Fujian, China;
    b State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, Fujian, China;
    c National Engineering Research Center of Chemical Fertilizer Catalyst, Fuzhou University, Fuzhou 350002, Fujian, China
  • Received:2015-08-29 Revised:2015-09-24 Online:2015-12-02 Published:2015-12-07
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21273036, 21177024) and the National Basic Research Program of China (973 Program, 2014CB239303).

摘要:

环境污染和能源短缺是制约当今社会发展的重大问题.光催化技术可直接利用太阳能驱动一系列重要的化学反应,具有能耗低、反应条件温和、无二次污染等优点,是解决这一问题的有效途径.实现这个过程的关键在于寻找设计高效的光催化剂.目前,光催化材料主要由无机半导体组成,其结构的改造和修饰难度很大,难以根据实际需要来控制其大小、形状以及物理化学特性.而有机化合物具有优良的分子剪裁与修饰的功能,但它们却在坚固性与稳定性等方面具有明显的缺点.因此如果能发展既具有无机化合物的稳定性又具有有机化合物的可剪裁与修饰性的新型光催化材料,无疑将促进光催化的发展和应用.
金属-有机骨架材料(Metal-Organic Frameworks, MOFs)正是这样一类结合了无机物的稳定性和有机物的可修饰性的杂化材料.MOFs是一类以金属阳离子为节点、有机配体为连接体的多孔配位聚合物的总称.这类材料不仅拥有超高的比表面积、丰富的拓扑结构,而且其结构兼具可剪裁性、可设计性、易调变等特点,在气体吸附储存、分离、传感等领域都有广泛的应用.在催化领域MOFs也显示出巨大的应用前景:(1)比表面积大,有利于对反应底物的吸附,促进催化反应的进行;(2)组成多样,结构具可剪裁性、可设计性、易调变等特点,通过对其金属单元或者配体进行改变修饰,可以实现对MOFs结构和性能的调变;(3)MOFs中金属-氧单元之间由有机配体隔开,相当于分立的半导体量子点,在反应中不易发生团聚.并且各个分立的金属-氧单元之间可能存在协同效应,有利于保持催化剂的稳定性和产生高的催化活性.因此,MOFs材料是一类非常有潜力的异相催化剂.光催化是一类典型的多相催化技术,与传统半导体光催化材料相比,MOFs由于具有可在分子水平进行灵活调控的优点,在光催化领域的应用更有优势.此外,MOFs结构上的确定性为研究催化剂的界面电荷迁移和光催化机理提供了便利条件, 通过对其构-效关系的研究和光催化反应机理的探索反过来有助于我们从微观尺度上进一步认识光催化的本质.
MOFs材料在光催化领域已经有了初步的研究.越来越多的MOFs材料被成功应用于光催化降解染料、选择性转化有机物、光解水制氢和CO2还原等反应.典型的有MOF-5、UiO-66和MIL-125系列等.近年来,已有少量的文献综述了MOFs这类材料在光催化领域的研究.这些文献主要围绕MOFs在光催化过程中所起到的作用,比如作为催化剂、助催化剂或载体来展开;或者是从MOFs的光催化应用领域,比如污染物降解、产氢、二氧化碳还原、有机物转化来分类展开.本文围绕如何设计合成高效的MOFs光催化剂,综述了近年来国内外关于提高MOFs的光催化性能而开展的相关研究工作,包括理论研究MOFs的能级结构及化学性质、在MOFs配体上修饰官能团调变其能带结构、染料或者金属化合物光敏化MOFs提高其光吸收性能、负载金属/碳材料及半导体复合提高光生载流子的分离效率等.最后,本文对MOFs光催化剂的未来发展趋势进行了展望,强调开发新型的MOFs光催化剂,并加强对MOFs光催化机制的研究,有助于指导现有MOFs催化剂的改良和设计新型光催化剂.

关键词: 金属-有机骨架材料, 光催化, 配体, 功能化, 光敏化, 助催化剂, 复合材料

Abstract:

Environmental pollution and energy deficiency represent major problems for the sustainability of the modern world. Photocatalysis has recently emerged as an effective and environmentally friendly technique to address some of these sustainability issues, although the key to the success of this approach is dependent on the photocatalysts themselves. Based on their attractive physic chemical properties, including their ultrahigh surface areas, homogeneous active sites and tunable functionality, metal-organic frameworks (MOFs) have become interesting platforms for the development of solar energy conversion devices. Furthermore, MOFs have recently been used in a wide variety of applications, including heterogeneous photocatalysis for pollutant degradation, organic transformations, hydrogen production and CO2 reduction. In this review, we have highlighted recent progress towards the application of MOFs in all of these areas. We have collected numerous reported examples of the use of MOFs in these areas, as well as providing some analysis of the key factors influencing the efficiency of these systems. Moreover, we have provided a detailed discussion of new strategies that have been developed for enhancing the photocatalytic activity of MOFs. Finally, we have provided an outlook for this area in terms of the future challenges and potential prospects for MOFs in photocatalysis.

Key words: Metal-organic frameworks, Photocatalysis, Ligand, Functionalization, Photosensitization, Co-catalyst, Composite