CAS: Molecular Design of Photoactive Covalent Organic Frameworks Capable of Reductive and Oxidative Degradation of Perfluoroalkyl Substances

在化学系化学催化项目的支持下，莱斯大学的Thomas Senftle教授和Rafael Verduzco教授正在研究开发新的光催化材料来处理被多氟烷基物质(PFAS)污染的水。全氟辛烷磺酸分子统称为“永久化学物质”，因为它们不会在环境中自然分解，可以在水、土壤和食物来源中积累。鉴于这些永久化学品带来的健康风险，迫切需要新的方法来消除我们水道中的全氟辛烷磺酸污染。为了解决这个问题，研究小组将开发纳米结构、高度多孔的材料，这些材料也具有光催化活性，使全氟辛烷磺酸能够同时吸附和降解，从而将它们转化为良性产品。具体地说，该团队正在开发光化学活性共价有机骨架(COF)，用于从水中去除全氟辛烷磺酸。COF是完全有机的大分子，具有蜂窝状的分子结构，莱斯的科学家将寻求设计这些材料，使其与PFAS强烈相互作用，以进行吸附和光化学降解。该项目有可能推动开发低成本的方法来修复全氟辛烷磺酸污染的水，最终开发出可持续和经济上可行的水处理方法。该项目还将建立新的外联活动。PIS将接待来自当地社区大学的学生，为那些原本研究机会有限的学生提供动手实验室体验。PIS还将通过莱斯大学的教师研究经验(RET)项目与当地一所高中的教师合作，该项目将产生高质量的学习模块，以支持休斯顿地区的K-12 STEM教育。在该项目下，Senftle博士和Verduzco博士及其团队将应用计算和实验方法开发共价有机骨架(COF)作为光催化剂来降解多氟烷基物质(PFAS)。COF的模块化性质为调节它们与全氟辛烷磺酸分子的相互作用提供了几种途径，可用于增强吸附和控制催化降解机制。该小组将研究一系列主链和侧链官能化变化的COF结构，预计将加强这一研究，以提供控制COFS中光催化PFAS降解机理的结构-性质关系的知识。模拟和实验的结合使用有望使人们更好地理解影响COF作为吸附剂和光催化剂的性能的物理机制。研究的重点将集中在澄清电子尺度上的光电性质的影响，以更好地理解原子尺度上的分子扩散和吸附。该项目旨在提出新的设计原则，以增强全氟辛烷磺酸在光催化COF材料中的吸附和降解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Chemical Catalysis program in the Division of Chemistry, Professors Thomas Senftle and Rafael Verduzco of Rice University are studying the development of new photocatalytic materials for treating waters contaminated with poly- and perfluoroalkyl substances (PFAS). PFAS molecules are collectively known as “forever chemicals” because they do not break down naturally in the environment and can accumulate in water, soil, and sources of food. Given the health risks posed by such forever chemicals, new methods are urgently needed for removing PFAS contamination from our waterways. To address this problem, the research team will develop nanostructured, highly porous materials that are also photocatalytically active, enabling the simultaneous adsorption and degradation of PFAS to convert them to benign products. Specifically, the team is developing photochemically-active covalent organic frameworks (COFs) for removal of PFAS from water. COFs are fully organic macromolecules with a honeycomb-like molecular structure, and the Rice scientists will seek to engineer these materials to interact strongly with PFAS for both adsorption and photochemical degradation. This project has the potential to advance the development of low-cost approaches for remediating PFAS-contaminated water, toward ultimately developing sustainable and economically viable approaches for water treatment. The project also will establish new outreach activities. The PIs will host students from a local community college to provide hands-on laboratory experience for students who otherwise would have limited research opportunities. The PIs also will work with teachers from a local high school through a Research Experiences for Teachers (RET) program at Rice University, which will produce high-quality learning modules to bolster K-12 STEM education in the Houston area.Under this project, Drs. Senftle and Verduzco and their team will apply computational and experimental methods to develop covalent organic frameworks (COFs) as photocatalysts for the degradation of poly- and perfluoroalkyl substances (PFAS). The modular nature of COFs offers several avenues for tuning their interactions with PFAS molecules, which can be used to enhance adsorption and control catalytic degradation mechanisms. The group will study a series of COF structures with variations in backbone and side-chain functionalization, which is expected to enhance to provide knowledge of the structure-property relationships that govern photocatalytic PFAS degradation mechanisms in COFs. The combined use of simulation and experiment is expected to lead to an improved understanding of the physical mechanisms that influence COF performance both as an adsorbent and a photocatalyst. Studies will focus on clarifying the influence of optoelectronic properties at the electronic scale to better understanding molecular diffusion and adsorption at the atomic scale. The project aims to deliver new design principles for enhancing PFAS adsorption and degradation in photocatalytic COF materials.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.