NSF Award
2003337
Abstracts for RUI: Modulation of cation exchange using oxidation/reduction to design plasmonic nanoheterostructures DMR-2003337 <br/> <br/>PART 1: NON-TECHNICAL SUMMARY<br/>One route to create next-generation nanomaterials is by taking single nanoparticles and transforming them into more complex structures. The process starts with one form of nanoparticle and trades out one type of atom for another. This leaves the nanoparticle with the same size and shape it started with, but with additional chemical components. This useful, but not yet fully understood, process is called cation exchange. This project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, uncovers how one can change the outcome of cation exchange by altering the features of the starting nanoparticle. It is expected that this will affect how much the particle changes in chemistry and where the new components go. It will also change the way the particles absorb light. The insights into how cation exchange works gained through these experiments will allow control over chemistry and structure on the nanoscale. This will eventually make it possible to design and create complex nanodevices that have a broad range of applications that are important to society, particularly in sensing and solar energy conversion. In addition to the benefits that come from directly from the science, training in materials chemistry will be strengthened through undergraduate research and an innovative partnership between laboratories at a primarily undergraduate institution and at an R1 university. Research infrastructure in the Central Pennsylvania region will be supported and barriers to broad participation in chemistry and materials will be reduced. <br/><br/>PART 2: TECHNICAL SUMMARY<br/>Starting with copper sulfide nanoparticles, designed nanoheterostructures are created through selective introduction of new components through cation exchange. Preliminary data show that iodine oxidation of roxbyite nanoparticles alters the propensity for cation exchange with cadmium and zinc ions as it simultaneously alters the localized surface plasmon resonance of copper sulfide particles. It is proposed that oxidation/reduction processes can be employed as tools to modulate chemical and spatial selectivity of partial cation exchange. This project, supported by the Solid State and Materials Chemistry program within the Division of Materials Research, seeks to reveal structure-property relationships affected by the alteration of copper sulfide nanoparticles through redox processes and to utilize these relationships to design novel plasmonic nanoheterostructures. The project examines various means of oxidation and reduction and elucidates the effects on structure, Cu-ion vacancy concentration, plasmonic behavior, and propensity for cation exchange in copper sulfide nanoparticles. The fundamental insights uncovered by the proposed work will advance our ability to control chemistry and structure on the nanoscale. The particles investigated have the potential to act as catalysts, solar energy absorbers in PV or solar water evaporation, NIR absorbers in photothermal cancer treatment, or sensors. Training in materials chemistry will be strengthened through undergraduate research with close student-faculty interaction and an innovative partnership between laboratories at a primarily undergraduate institution and at an R1 university. Research infrastructure in the Central Pennsylvania region will be supported and barriers to broad participation in chemistry and materials research will be reduced.<br/><br/>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.
