CAREER: Rational Design of Efficient Carbon Nanotube-Supported TiO2 Photocatalysts for Air Purification

PI姓名：Amama提案编号：1653527 NO2是美国环境保护署规定的六种优先空气污染物之一，与健康问题（肺部疾病，中风，缺血性心脏病和癌症），地面臭氧的形成和细颗粒污染有关。在紫外线（UV）光下，二氧化钛（TiO 2）可将空气中的低水平NOx（~1 ppm或以下）氧化为无害的硝酸盐。该项目将为碳纳米管（CNT）和TiO 2的耦合提供框架，目标是实现低成本和大面积的CNT基/TiO 2涂层，用于有效的户外污染控制。预计这项技术将大大改善城市空气质量，并从源头上消除臭氧。教育计划将同时推进科学发现，增加科学，技术，工程和数学（STEM）管道，以及装备工程专业学生在堪萨斯州立大学（KSU）的技能，创新和成功的职业生涯在纳米技术。这个项目的目标是整合纳米技术和多相催化，以制造定制和多功能的CNT-用于环境修复的复合材料。PI将测试广泛的假设，即碳纳米管负载的二氧化钛纳米复合材料（CNT/二氧化钛）的光催化活性和光响应增强的碳纳米管的性能和所得的界面电荷转移性能。研究目标将通过追求以下具体任务来实现：1）高度均匀的碳纳米管[金属单壁碳纳米管]的可规模化合成（m-SWCNT）、半导体SWCNT（s-SWCNT）和多壁CNT（MWCNT）]的方法; 2）使用UV光和绿色溶剂（H2 O2）控制CNT官能化和CNT与TiO 2的偶联; 3）阐明CNT和TiO 2之间的耦合机制;和4）评价CNT/TiO 2在各种环境和材料变量下在NOx氧化中的光催化活性。本研究将阐明二氧化钛与碳纳米管之间的耦合机制，并建立结构-性能-功能关系。这项工作是一种新的手段，最大限度地提高电荷分离效率的二氧化钛和扩展其光响应到可见光区。所得到的s-SWCNT/TiO 2光催化剂将为合成可见光活性、低成本、高效和大面积的CNT基/TiO 2涂层用于NOx的光催化氧化提供变革性途径。为s-SWCNT和m-SWCNT创建一种可扩展和受控的CVD合成方法，其数量级高于传统的后纯化方法，这将是变革性的，因为这是可扩展合成定制的SWCNT/TiO 2光催化剂的必要的第一步。在TiO 2沉积过程中使用UV/H2 O2进行CNT功能化将确保电子沿着CNT自由穿梭;这种方法不同于传统方法，传统方法主要涉及使用侵蚀性酸处理，从而在CNT上产生显著缺陷。CNT/TiO 2光催化剂的结构-性质-功能相关性将大大提高对耦合机制的理解，并为在许多光催化应用中采用纳米复合材料奠定坚实的基础，包括水分解，空气净化，CO2还原，水净化和微生物灭活。国际交流计划将有利于双方的研究和教育在堪萨斯州立大学，美国学生将获得宝贵的全球视野-一个关键技能的工程师在21世纪世纪。

PI Name: AmamaProposal Number: 1653527 NO2 is one of six priority air pollutants regulated by the US Environmental Protection Agency and has been linked to health problems (lung diseases, strokes, ischemic heart disease, and cancer), formation of ground-level ozone, and fine-particle pollution. Under ultraviolet (UV) light, titanium dioxide (TiO2) oxidizes low-level NOx (~1 ppm or below) in air to harmless nitrates. This project will provide the framework for the coupling of carbon nanotubes (CNTs) and TiO2 with the goal of enabling low-cost and large-area CNT-based/TiO2 coatings for efficient outdoor pollution control. This technology is expected to provide significant improvement in urban air quality and combat ozone at the source. The educational plan will simultaneously advance scientific discovery and increase the science, technology, engineering, and mathematics (STEM) pipeline, as well as equip engineering students at Kansas State University (KSU) with skillsets for innovative and successful careers in nanotechnology.The objective of this project is to integrate nanotechnology and heterogeneous catalysis to fabricate well-tailored and multifunctional CNT-based composites for environmental remediation. The PI will test the broad hypothesis that photocatalytic activity and photoresponse of CNT-supported TiO2 nanocomposites (CNT/TiO2) are enhanced by the properties of CNTs and resulting interfacial charge transfer properties. The research goal will be achieved by pursuing the following specific tasks: 1) scalable synthesis of highly uniform CNTs [metallic single-walled CNTs (m-SWCNTs), semiconducting SWCNTs (s-SWCNTs), and multiwalled CNTs (MWCNTs)] using an industrial waste gas from Fischer-Tropsch synthesis as a feedstock; 2) controlled CNT functionalization and coupling of CNTs and TiO2 using UV light and a green solvent (H2O2); 3) elucidation of the coupling mechanisms between CNTs and TiO2; and 4) evaluation of the photocatalytic activity of CNT/TiO2 in the oxidation of NOx under various environmental and material variables. This study will illuminate the coupling mechanisms between TiO2 and CNTs and establish structure-property-function relationships. The work is a novel means for maximizing charge-separation efficiency of TiO2 and extending its photoresponse to the visible-light region. The resulting s-SWCNT/TiO2 photocatalyst will provide a transformative pathway for the synthesis of visible-light-active, low-cost, efficient, and large-area CNT-based/TiO2 coatings for the photocatalytic oxidation of NOx. Creation of a scalable and controlled CVD synthesis approach for s-SWCNTs and m-SWCNTs that are orders-of-magnitude higher than conventional post-purification methods will be transformative, as it is a necessary first step for scalable synthesis of well-tailored SWCNT/TiO2 photocatalysts. The use of UV/H2O2 for CNT functionalization during TiO2 deposition will ensure that electrons are freely shuttled along the CNTs; this approach differs from conventional approaches, which largely involve the use of aggressive acid treatment that imparts significant defects on CNTs. The resulting structure-property-function correlations of CNT/TiO2 photocatalysts will substantially improve understanding of the coupling mechanisms and lay a solid foundation for the adoption of the nanocomposites in a number of photocatalytic applications including water splitting, air purification, CO2 reduction, water purification, and microbial inactivation. The international exchange program will benefit both research and education at KSU, as US students will gain valuable global perspective--a critical skill for an engineer in the 21st century.