贱金属游离超薄膜的仿生合成及其与窄带半导体纳米柱的交替组装和可见光催化降解有机污染物研究

With the advent of graphene, the two-dimensional materials rapidly become a research hotspot, and various kinds of two-dimensional materials have emerged. However, monolayer or quasi monolayer two-dimensional ultrathin membranes are still difficult to prepare, not to say the ultrathin membranes dissociated from the substrates. Limited by the metallic bonds’ directionless and the metal atoms’ active features, the preparation of base metal dissociated ultrathin membranes (BMDTMs) is still an unsolved problem. In this project, the iron series BMDTMs will be prepared by supported liquid membrane biomimetic synthesis. Then, based on the electrical conductivity, transparency, magnetism and stereoscopic assembly of the membranes, the BMDTMs and narrow band semiconductor nano pillars (NSNPs) will be alternately assembled using the seed growth technique and the layer-by-layer assembly method, which will produce a series of [NSNPs-BMDTMs]n sandwiched porous three-dimensional hetero-structured multifunctional materials with excellent photocatalytic degradation property for organic pollutants. The materials include various construction units used to regulate their performance, such as “hetero-junction”, “transparent membrane”, “electrical conductivity”, “stereoscopy”, “nano-array”, “pore structure”, “magnetic function” and “visible light absorption”. When used for visible light photo-degradation of organic pollutants, the catalytic efficiency, sunlight utilization and the cycle life of photocatalysts will be greatly improved. In this project, not only new materials and new structures will be created, but also new function and high efficiency will be obtained, which is of great significance.

随着石墨烯的问世，二维材料迅速成为研究热潮，各类二维材料相继涌现，但单层或准单层二维超薄膜却较难制备，脱开基底的游离超薄膜则更难获得，而贱金属游离超薄膜的制备受制于金属键的无方向性和原子的活泼性使之成为尚未突破的难题。本项目拟采用支撑液膜仿生合成法制备铁系等贱金属游离纳米超薄膜（BMDTMs）；然后利用该膜的导电性、透明性、磁性和可立体组装性，通过种子生长技术和层层组装手段，与窄带半导体纳米柱（NSNPs）进行交替组装，制备一系列对环境有机污染物具有优异光催化降解性能的[NSNPs–BMDTMs]n夹层多孔立体异质结构多功能材料。该材料囊括了“异质结”“透光膜”“导电性”“立体化”“纳阵列”“孔结构”“磁功能”“可见光吸收”等多种可用来调控性能的结构单元。用于有机污染物的可见光催化降解可极大地提高催化效率、太阳光利用率和催化剂循环寿命。本项目不仅将创造新材料新结构，而且将获得新功能高效率。

目前，环境污染仍是人类社会面临的重大威胁之一。本项目针对难以控制的有机环境污染物降解难题，通过创建“胶棉液膜仿生法”、“温和水热仿生法”和“超柔性多级仿生法”等多种过程仿生合成新方法，设计制备出一系列以贱金属Co、Ni、Cu及NiCo合金游离超薄膜/片为基的BiOBr、Cu2O、Ag3PO4、WO3、Bi2MoO6等一系列窄带半导体复合超结构材料；并将其拓展到碳基上，组装成多种碳基贱金属半导体纳米复合材料。由于该系列材料内部囊括了超薄膜、透光性、异质结/同质结、孔结构、窄带半导体、高效电荷分离等多种可用于调控性能的结构单元，使之用于有机污染物及污染菌的可见光光催化处理时获得了快速、高效、廉价、可循环的良好效果。不仅实现了对有机染料类环境污染物的数分钟超快可见光催化降解，而且实现了对细菌类环境污染微生物的秒杀效应，还实现了对镍基水系电池高稳定性基础上的逼近理论容量，甚至实现了对纳米网络碳及其半导体复合网络结构的百万次乃至无限次超折叠性能的突破。. 本项目的完成，不仅获得了多种新的合成方法和一系列新型多功能材料，而且可以大大推进有机污染物光催化降解技术走向实用化的进程，为碳中和做出贡献。具有重要的科学意义和广阔的应用前景。