仿生活化氧功能金属酞菁-半导体复合材料的制备及其协同催化效应研究

Biomimetic catalytic oxidation as a low cost, high efficient and environmental friendly technology for pollutant control has been the great research interest in the field of environment science. The low cost and high stable biomimetic metal phthalocyanine (MPc) with the function of oxygen activation could not only biodegrade chemical contaminants, but also absorb the visual light in full solar spectra for the sensitization of semiconductor supports. Therefore, it is of significance that design and synthesis of novel biomimetic MPc complexes for construction of MPc-semiconductor composite materials. In this study we would load biomimetic tetranitro iron (II) phthalocyanine (TNFe(II)Pc) (or similar biomimetic MPc) with the function of oxygen activation on different semiconductor supports for preparation of various MPc-semiconductor composite catalysts. We would investigate the influence of the crystal structure and surface morphology of different semiconductors, the loading method and content of MPc on the catalytic activity of composite catalyst. The mechanism of charge transfer between MPc and semiconductor and the generation process of active species on composite catalyst was also studied. Moreover, the synergistic effect of biomimetic catalysis from MPc and photocatalysis from semiconductor would be investigated in detail for illuminating the catalytic mechanism. This study is significant for the development of novel MPc-semiconductor composite catalysts with the synergistic effect of biomimetic catalysis and photocatalysis,and presents a novel route for pollutant removal.

仿生催化氧化技术作为耗能低、效率高、环境友好的污染物控制方法一直受到环境科学界的重视，低成本、高稳定性的仿生活化氧功能金属酞菁不仅能够对污染物绿色降解，还能够吸收太阳光谱的可见光敏化半导体载体。因此，设计和开发新型仿生活化氧功能的金属酞菁并构建半导体复合材料实现仿生催化、可见光催化功能的集成具有重要的学术意义。本项目以最新发现的具有仿生活化O2功能四硝基铁(II)酞菁为模板化合物，拟通过改变半导体载体的晶体结构、表面形貌及控制金属酞菁的负载方式和负载量，设计具有高催化活性的金属酞菁-半导体复合材料，探究金属酞菁与半导体间的电荷迁移规律和各种活性物种产生规律，揭示金属酞菁与半导体间承担的仿生催化和光催化功能以及产生于二者间的协同催化作用机理，藉此开发具有仿生催化和光催化协同催化作用的新型金属酞菁-半导体复合催化剂，为环境污染物的治理开辟一条新途径。

基于具有活化氧分子功能的模板化合物四硝基铁(II)酞菁，我们发现了类似功能的八羧基铁(III)酞菁、四苯磺酸氧铁(III)酞菁、四喹啉磺酸氧铁(III)酞菁、四硝基铜(II)酞菁、锰(II)酞菁、八羧基钴(II)酞菁及八羧基锌(II)酞菁催化剂。其中八羧基铁(III)酞菁能够在均相条件下活化叔丁基过氧化氢(BuOOH)，锰(II)酞菁可经两种途径活化氧气为单线态氧和超氧阴离子自由基，利用四硝基铜(II)酞菁非均相催化的特点，将其设计成负载于磁性载体的Fe3O4@C@TNCuPc复合催化剂，与BuOOH可构建成催化氧化体系。以上三种催化体系均能以酚为底物将其催化氧化，用于酚类污染物的显色识别。另外，八羧基铁(III)酞菁、八羧基钴(II)酞菁及八羧基锌(II)酞菁能够将罗丹明B、亚甲基蓝等有机染料快速脱色，催化过程无需加热、光照，且无需其它化学助剂的加入。以上金属酞菁活化氧气、过氧化剂功能的实验研究有望为环境污染物的有效治理提供一条绿色、安全、低成本的新方法。