CAREER: 3D Printed Carbon-Metal Nanohybrid Aerogels for Highly Efficient Adsorptive/Catalytic Removal of PFASs

全氟和多氟烷基物质(PFAS)是一种氟化有机化学品，自20世纪40年代以来已被制造并用于许多消费品和工业应用。在过去的二十年里，越来越多的人在地表水、地下水、土壤、污泥和生物固体中检测到全氟辛烷磺酸，这引起了人们对其持久性、稳定性和对环境的不利影响(包括对生物和人类的毒性)的极大关注。传统的水处理技术无法有效地去除和销毁全氟辛烷磺酸，因为它们在受污染的水源中具有稀释浓度和独特的化学特性，包括强C-F键、疏水碳尾和亲水性末端基团的组合。这一职业项目的总体目标是为开发一种新型的集成过滤/催化反应器系统奠定基础，该系统可以从受污染的水源中提取和销毁全氟辛烷磺酸。为了推进这一目标，首席研究员建议使用3D打印来探索制备吸附/催化石墨烯-金属纳米杂化气凝胶的方法，该气凝胶具有高比表面积、表面化学可调、具有分层和相互连接的孔以实现快速水/质传输，从而能够有效地从受污染的水源中提取和降解全氟辛烷磺酸。该项目的成功完成将通过开发新的功能材料和基础知识来促进综合过滤和催化系统的开发，从而使社会受益，该系统可以为处理全氟辛烷磺酸污染的水提供使用点(POU)过滤器。通过学生教育和培训将进一步造福社会，包括指导布法罗大学的一名研究生和布法罗公立学校的四名中学/中学教师。基于石墨烯的气凝胶因其独特的结构特性而成为很有前途的水处理平台，包括具有高比表面积的分级/相互连接的毛孔，使水/质量快速传输，以及高效的材料再生和再利用。将光催化和/或氧化还原活性金属纳米材料集成到基于石墨烯的气凝胶中，有可能为设计和建立新一代集成过滤/催化系统提供新的机会，以有效和经济地处理全氟辛烷磺酸污染的水。作为实现这一目标的第一步，这一职业项目的首席研究员(PI)建议利用PI实验室开发的独特3D打印方法来探索制造可调、独立、水稳定和多功能的光/氧化还原催化石墨烯-金属纳米杂化气凝胶，作为安全有效的平台来处理和降解PFAS。本研究的具体目标是：(1)开发一种用于催化石墨烯-金属纳米杂化气凝胶的3D打印方法，并使用包括纳米分辨率的X射线计算机断层扫描在内的最新技术来表征气凝胶的性质；(2)研究PFAS的吸附程度和催化降解、石墨烯气凝胶的尺寸和孔隙率以及水化学(包括pH、离子强度和天然有机物对材料性能的影响)之间的关系；(3)利用统计建模和傅立叶变换红外光谱(FT-IR)、X射线光电子能谱(XPS)、电子顺磁共振(EPR)、高分辨质谱联用(LC-HRMS)和离子色谱(IC)等分析手段，研究了三维打印石墨烯气凝胶对PFAS的吸附和降解机理。该项目的成功完成有可能通过开发新的吸附/催化材料和产生新的基础知识来推动综合过滤/催化系统的开发，这些系统可用作处理全氟辛烷磺酸污染水的使用点(POU)过滤器。为了实现这一职业项目的教育和培训目标，国际和平研究所将在布法罗大学开发一门新的本科生/研究生课程，重点是纳米材料的合成、加工和环境修复应用。此外，PI计划与布法罗公立学校(BPS)系统的教师合作，制定教案，向初中生传授环境污染和补救知识。这一奖项反映了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。

Per- and polyfluoroalkyl substances (PFAS) are fluorinated organic chemicals that have been manufactured and used in numerous consumer products and industrial applications since the 1940s. During the last two decades, increasing detection of PFAS in surface water, groundwater, soils, sludges, and biosolids has raised significant concerns about their persistence, stability, and adverse impact in the environment including toxicity to living organisms and humans. Conventional water treatment technologies cannot effectively remove and destroy PFAS due to their dilute concentration in contaminated water sources and unique chemical features, including a combination of strong C-F bonds, hydrophobic carbon tails, and hydrophilic terminal head groups. The overarching goal of this CAREER project is to lay the foundation for the development of a novel and integrated filtration/catalytic reactor system that can extract and destroy PFAS from contaminated water sources. To advance this goal, the Principal Investigator proposes to use 3D printing to explore the fabrication of adsorptive/catalytic graphene-metal nanohybrid aerogels with high surface area, tunable surface chemistry, and hierarchical and interconnected pores for fast water/mass transport to enable efficient extraction and degradation of PFAS from contaminated water sources. The successful completion of this project will benefit society through the development of new functional materials and fundamental knowledge to advance the development of an integrated filtration and catalytic system that could serve a point-of-use (POU) filter for the treatment of PFAS contaminated water. Further benefits to society will be achieved through student education and training including the mentoring of a graduate student at the University at Buffalo and four middle/school teachers from the Buffalo public schools.Graphene-based aerogels have emerged as promising water treatment platforms due to their unique structural properties including hierarchical/interconnected pores with high surface area that enable fast water/mass transport, and efficient material regeneration and reuse. The integration of photocatalytic and/or redox-active metallic nanomaterials into graphene-based aerogels have the potential to open new opportunities to design and build a new generation of integrated filtration/catalytic systems for the efficient and cost-effective treatment of PFAS contaminated water. As a first step toward this goal, the Principal Investigator (PI) of this CAREER project proposes to leverage a unique 3D printing approach developed in the PI’s laboratory to explore the fabrication of tunable, self-standing, water-stable, and multifunctional photo/redox-catalytic graphene-metal nanohybrid aerogels as safe and effective platform for PFAS treatment and degradation. The specific objectives of the research are to: (1) Develop a 3D printing approach for catalytic graphene-metal nanohybrid aerogels and characterize the aerogel properties using state-of-the-art techniques including X-ray computed tomography with nanoscale resolution; (2) Investigate the relationships between the extents of PFAS sorption and catalytic degradation, graphene aerogel size and porosity, and water chemistry including the effects of pH, ionic strength, and natural organic matter on material performance; and (3) Elucidate the mechanisms of adsorption and degradation of PFAS by the 3D printed graphene aerogels using statistical modeling and a combination of analytical tools including Fourier transformed infrared (FT-IR) spectroscopy, X-Ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) spectroscopy, liquid chromatography coupled with high resolution mass spectrometry (LC-HRMS), and ion chromatography (IC). The successful completion of this project has the potential for transformative impact through the development of new adsorptive/catalytic materials and the generation of new fundamental knowledge to advance the development of integrated filtration/catalytic systems that could serve as point-of-use (POU) filters for the treatment of PFAS contaminated water. To implement the educational and training goals of this CAREER project, the PI will develop a new undergraduate/graduate course at the University at Buffalo that will focus on nanomaterial synthesis, processing, and applications to environmental remediation. In addition, the PI plans to collaborate with teachers from the Buffalo Public Schools (BPS) system to develop lesson plans to teach middle/high school students about environmental pollution and remediation.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.