This proposal was received in response to Nanoscale Science and Engineering initiative, NSF 02-148, category NER. This proposal aims at investigating an innovative method to prepare nanostructured TiO2 photocatalytic powders and immobilized films with enhanced surface area, tailor-designed pore structure, and increased catalyst activity. The method concerns an alternative sol-gel procedure that employs a New Generation of "Green" Designer Solvents, known as Room Temperature Ionic Liquids (RTILs). The method will also include the use a combination of RTIL-based sol-gel methods and self-assembling templates for controlling the pore characteristics of the nanoparticles and films.
Both nanoparticles and immobilized films will be characterized using state-of-the-art instrumentation and will be evaluated for their photocatalytic activity. The intellectual merit of the proposal is its high novelty of using a new generation of green solvents to engineer the properties of advanced materials. The PI will explore the role of ionic liquid structure on these reactions and how such properties affect the size and porosity of the final layer film. The study will examine the influence of process conditions (solvent removal, heat treatment) during the calcination and crystallization of the final film. The proposal is novel and has high risk. However, based on known properties of some of these WIRTILs (water immiscible room temperature ionic liquids) and the deep understanding of the sol-gel/heat treatment procedures for the preparation of TiO2 photocatalyst, there is adequate rationale for the success of this project. New concepts in material processing will be introduced. If such project proves successful, it will pioneer the processing of advanced materials using sol-gel methods and will "leap-frog" the application of a new class of Green Solvents in Nanotechnology, materials processing, and environmental applications.
The broader impacts of this proposal are tremendous. This idea can be applied for the synthesis of other types of oxides and oxide-oxide or metal-oxide composites in powder or as immobilized films. It is expected that this study will propel the use of ionic liquids in the processing of other advanced nanoporous materials. Potential markets will include chemical, pharmaceutical, and environmental industries (catalysis, chemical synthesis, electrochemistry, separations, oxidation). The societal impact can be high since it will create new synthetic routes for the manufacture of nanomaterials with novel properties and will extent the application of a new class of environmentally friendly solvents. The project will also include a strong educational component, which will integrate innovative concepts in materials science, chemistry, chemical engineering, and environmental engineering for the processing of advanced nanomaterials. Students in all these disciplines will have the opportunity to get involved in new courses dealing with the application of Green Chemistry and Green Engineering in chemical synthesis and Environmental Nanotechnology.
