Nanoparticles In Solids And Solutions

Author : Connor Mc Cormick
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (142 download)

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Download or read book Discovery and Design of Heterostructured and Solid Solutioned Nanoparticles written by Connor Mc Cormick and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthetic strategies to develop increasingly more complex nanoparticle materials have grown in relevance in recent decades as nanoparticle-based technologies have developed. Specifically, in applications of optics, photocatalysis, thermoelectrics, and medical fields, where having multiple nanomaterials combined in a single nanoparticle, a heterostructure, allows access to multiple functionalities within a single construct. In addition to these additive strategies, precision in physical outcome has been achieved in solid solution nanoparticles, which are alloys of two distinct materials. Designing scalable and solution processable methods to access such materials is far from optimized. Many methods of discovery and design rely on non-scalable methodologies, minimizing their impacts as a basis for retrosynthesis of complex nanoparticles. Colloidal chemistry offers an avenue for fundamentally scalable and solution processable syntheses, but insights into synthetic outcomes can be obscured by the multitude of variables synthesis to synthesis. Specifically, cation exchange is leveraged to generate these heterostructures and solid solutions. Cation exchange is chemical transformation that replaces the host cations in a template material with guest cations from solution. This chemistry has been utilized to generate robust chemistry to design heterostructures and solid solutions. This dissertation contains works that further the goal of developing syntheses to target complex heterostructure and solid solution constructs. Specifically, in chapter 2 I utilize simultaneous multi-cation exchange to generate products with a high number of products. Then through trends in compositions and interfacial arrangement, I iterate different synthetic conditions and re-evaluate product outcomes to determine which product features are targetable and synthetically achievable. Then, these observations of small populations are used to develop syntheses for high-yield targeted syntheses of previously unattainable products. Specifically, high yield syntheses of a (Ni,Co)xS solid solution and two isomers, ZnS - Cu1.8S - (Ni,Co)xS and ZnS - (Ni,Co)xS - Cu1.8S, are realized. The isomers are generated through a different sequence of cation injections. This work serves as a template of how to do exploratory syntheses to discover new and achievable products. Then, building on the observations in chapter 2, I investigate the formation of a high entropy metal sulfide, wurtzite-type Zn0.25Co0.22Cu0.28In0.16Ga0.11S in chapter 3. The formation of a high entropy material was surprising, as typical high entropy material syntheses rely on high temperatures and rapid quenches to trap the high entropy phase. I, however, use cation exchange which leaves the anion scaffolding unaltered and allows for the incoming cations to react with the copper sites to form the solid solution. It is shown that the reaction is not generalizable to make any solid solution but does allow for compositional tuning. Overall, the formation of the high entropy material through cation exchange is revealed to behave similarly to the formation of single cation metal sulfides made through cation exchange. Returning to observations in chapter 2, I investigate the formation of a zinc cobalt sulfide, CoxZn1-xS, solid solution in chapter 4. This solid solution phase is verified to be a metastable phase through DFT modelling in collaboration with Ismaila Dabo and Steven Baksa. Synthetically, the formation of the solid solution is observed across three morphologies (spheres, plates, and rods) of Cu1.8S used as the template material. However, targeting larger amounts of cobalt in the CoxZn1-xS in the nanorods and nanoplates resulted in phase segregation. On Cu1.8S spheres, the full composition range (0