US-EGYPT Cooperative Research: Polycyclic Aromatic Hydrocarbon Degradation by Nanostructured TiO2 Thin Films

美国-埃及合作研究：纳米结构TiO2薄膜降解多环芳烃

• 批准号: 0809174
• 负责人: S. Ismat Shah
• 金额: $ 2.99万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0809174&HistoricalAwards=false
• 关键词: US; EGYPT; Cooperative; Research; Polycyclic

0809174ShahDescription: This project supports collaborative research by Dr. S. Ismat Shah, Department of Materials Science and Engineering, University of Delaware-Newark. The Egyptian collaborator is Dr. Ahmed Aboul Gheit of the Egyptian Petroleum Research Institute, Cairo, Egypt. They plan to study Polycyclic Aromatic Hydrocarbons (PAHs) degradation. The project includes a systematic study of the synthesis process, characterization of the modified materials, and the degradation mechanism. PAHs are a group of more than 100 chemicals that are emitted when fossil fuels are used under conditions that lead to incomplete burning. Some PAHs are manufactured. They are colorless, white, or pale yellow-green solids. PAHs affect body immune system (effect confirmed only in animals) and are know carcinogens. In addition to their presence in air, they also make their way into the water systems either indirectly from the atmosphere or directly through the industrial waste. This proposal describes a methodology through which a tried and tested material, titanium dioxide (titania), will be used in a unique form (nanostructured thin film) which will allow the known properties of titanium dioxide to be exploited more efficiently for the degradation of PAHs in water. Bulk titania works only with the ultra-violet (UV) light. If natural degradation is desired, titania has to be modified so that the larger portion of the sunlight, the visible light, could be made useful. The heart of the project is to modify titania such that a structure could be formed that is sensitive to visible light. Intellectual Merit: This proposal describes a detailed study of photodegradation of Polycyclic Aromatic Hydrocarbons (PAHs) in water in the presence of a photocatalyst composed of semiconductor metal oxides. PAHs are carcinogens and are present in air and in water. They emanate primarily from incomplete combustion of fossil fuels. The photocatalyst (TiO2) will be in the form of thin films that are fabricated such that there is strong adhesion with the substrates, e.g., glass, etc. The thin film processes to be used include sol-gel, metalorganic chemical vapor deposition (MOCVD), and pulsed laser deposition (PLD). The photodegradation intermediates will be traced using high performance liquid chromatography analysis and degradation reaction path will be studied for samples irradiated at different periods with different irradiation strengths using UV and visible light. Extensive catalysts characterization will be carried out using various techniques including diffraction, microscopy and spectroscopy methods. Furthermore, the composition of the catalyst will be optimized for the phases present (anatase/rutile) or with the addition of dopant, particularly nitrogen, to the principle TiO2 catalyst to enhance its photocatalytic activity. The presence of the nanostructure in the TiO2 thin film form is the unique aspect of this study. Experiments will exploit the additional advantages the nanomaterials provide over bulk material, namely higher surface area, presence of more active metastable phases, and modified band structure better suitable for photocatalysis. Broader Impacts: The project addresses a problem of significant environmental and health impact. The collaboration between Egyptian and US scientists and engineers will be beneficial to both sides. Several U.S. and Egyptian undergraduate and graduate students will be involved in the proposed work. The PI has successfully worked with his Egyptian counterparts, including publishing several joint publications. This project is being supported under the US-Egypt Joint Fund Program.

0809174 Shah描述：该项目支持S. Ismat Shah，特拉华大学纽瓦克分校材料科学与工程系。 埃及的合作者是埃及开罗埃及石油研究所的Ahmed Aboul Gyndham博士。他们计划研究多环芳烃（PAHs）的降解。 该项目包括合成过程的系统研究，改性材料的表征和降解机理。多环芳烃是一组100多种化学物质，当化石燃料在导致不完全燃烧的条件下使用时会排放出来。一些多环芳烃被制造出来。它们是无色、白色或浅黄绿色固体。多环芳烃影响人体免疫系统（仅在动物中证实），是已知的致癌物质。除了存在于空气中之外，它们还间接地从大气中或直接通过工业废物进入水系统。该提案描述了一种方法，通过该方法，经过试验和测试的材料二氧化钛（二氧化钛）将以独特的形式（纳米结构薄膜）使用，这将允许更有效地利用二氧化钛的已知特性来降解水中的多环芳烃。块状二氧化钛只在紫外线（UV）光下工作。如果需要自然降解，则必须对二氧化钛进行改性，以便使更大部分的阳光，即可见光，可以使用。该项目的核心是对二氧化钛进行改性，以便形成对可见光敏感的结构。智力优势：本研究以半导体金属氧化物为光催化剂，对水中多环芳烃（PAHs）的光催化降解进行了详细的研究。多环芳烃是致癌物质，存在于空气和水中。它们主要来自化石燃料的不完全燃烧。光催化剂（TiO 2）将是薄膜的形式，其被制造成使得与基底具有强的粘附力，例如，使用的薄膜工艺包括溶胶-凝胶、金属有机化学气相沉积（MOCVD）和脉冲激光沉积（PLD）。将使用高效液相色谱分析追踪光降解中间体，并将使用紫外光和可见光研究在不同时间段以不同辐照强度辐照的样品的降解反应路径。广泛的催化剂表征将使用各种技术，包括衍射，显微镜和光谱方法进行。此外，催化剂的组成将针对存在的相（金红石/金红石）进行优化，或者将掺杂剂（特别是氮）添加到主要TiO 2催化剂中以增强其光催化活性。在TiO 2薄膜形式的纳米结构的存在是本研究的独特方面。实验将利用纳米材料提供的额外优势，即更高的表面积，更活跃的亚稳相的存在，以及更适合于纳米材料的改性能带结构。更广泛的影响：该项目解决了一个对环境和健康有重大影响的问题。 埃及和美国科学家和工程师之间的合作将对双方都有利。 一些美国和埃及的本科生和研究生将参与拟议的工作。PI与埃及同行成功合作，包括出版了几份联合出版物。 该项目得到了美国-埃及联合基金计划的支持。