三蝶烯聚合物/金属硫化物复合催化剂能带调控机制及光解水性能研究

It is urgent for human beings to develop the new technology represented by hydrogen production utilizing solar energy, due to the environment and energy problems caused by the use of fossil fuels. Triptycene-based polymer/metal sulfide composite with controlled band-gap is proposed in this project, which can enhance the photocatalytic activity and stability. Based on the unique intrinsic molecular free volume and excellent capability of chemical reactions, the triptycene polymers are designed and synthesized by a series of methods, such as modification of organic linkers, replacement of metal ions and construction of π-π stacking structure. The band-gap of triptycene polymer can be regulated to match that of metal sulfide, achieving the effective separation of photogenerated electrons-holes of heterojunction catalyst. Study the relationship between the catalyst structure and photocataytic performance. Reveal the mechanism of the band-gap tuning of polymer on the photogenerated charge transfer paths and the reaction behaviors. Furthermore, the photocatalytic mechanism will be demonstrated. The present study is expected to develop a novel photocatalyst represented by porous triptycene-based polymer, providing a new strategy for designing and constructing highly efficient and stable photocatalysts.

使用化石燃料带来的环境与能源问题促使人类开发以太阳能制氢为代表的新技术。本项目拟通过构筑能带可控调变的三蝶烯聚合物/金属硫化物复合催化剂，提高光解水性能和光稳定性。基于三蝶烯独特的“富电子空穴”结构和丰富的化学反应性能，通过调节有机配体、改变金属离子、构筑π-π 堆积效应等方法调控三蝶烯聚合物的能级带隙，使之与金属硫化物的能带相匹配，从而实现复合催化剂光生电子和空穴的有效分离。本项目研究催化剂结构与光催化活性之间的构效关系，揭示聚合物能级带隙对复合催化剂光生电荷转移路径和反应行为的调控机制，阐明其光催化反应机理。通过本项目的研究，有望发展以三蝶烯多孔聚合物为代表的新型光催化剂，为高效、稳定光催化剂的设计和开发提供新途径。

太阳能光催化分解水可以将水直接转化成清洁、可再生的氢燃料，因而是解决能源短缺、环境恶化和气候变暖等问题的最理想的技术途径之一。但是光催化研究仍存在亟待解决的挑战性问题，例如光生电荷分离效率低、可见光吸收弱、比表面积小等。本项目围绕三蝶烯聚合物在光催化领域展开系统深入的研究，利用能带工程（组成、尺寸或异质）与结构设计（构筑单元）的协同调控方法来增强光的吸收与利用率以及缩短电荷传输的距离，通过构建半导体/三蝶烯聚合物等异质催化剂来促进电荷分离，从而提高电荷分离效率。具体研究成果分为以下三个方面：1、利用Suzuki偶联反应构建的新型三蝶烯共价聚合物TCP，与双金属硫化物复合后，表现出良好的光解水产氢活性和光稳定性；2、首次基于三蝶烯多孔聚合物构建核壳催化剂，在保留各组成部分固有特性的前提下，增加复合催化剂的界面接触，有效提高电荷传输效率；3、通过增加有机配体碳链长度，合成了新型三蝶烯的共价聚合物TMP，实现光催化剂孔径、能级可控。利用原位沉淀法制备了TMP-Cd0.5Zn0.5S复合光催化剂，进一步提高光生电荷分离，从而增强光催化分解水性能。在Chem. Eng. J.，J. Hazard. Mater.，Chem. Commun.等国际主流期刊上发表SCI论文12篇，授权专利3篇，其研究结果为半导体高效光生电荷迁移及光催化性能研究提供实验依据和理论指导。总之，本研究项目基本完成了计划书上规定的任务，达到了预期的研究目标。