열변색 에너지 응용을 위한 산화물 나노입자의 나노 비정질화 합성 공정

Abstract

Metal-oxide nanoparticles are essential materials due do their vital role in a wide range of potential applications including materials chemistry, electronics, biomedical, optical, and environmental energy applications. Due to the decrease in size in the nanoparticles, an increasing number of surface and interface atoms are produced enabling desirable novel magnetic, conducting, chemical, and electronic properties. Although metal-oxide nanoparticles have been demonstrated in small laboratory-scale, the development of cost-effective scalable methods of synthesis is necessary. In this dissertation, studies to explore and demonstrate the improved synthetic process by nano-amorphization of various inorganic nanoparticles (VO2, MoO3, (La0.6Sr0.4)CoO3, h-BN) for applications in thermochromism and oxygen evolution reaction catalysts are presented. Chapter 1 introduces the background and motivation of this thesis study. Oxide nanoparticles (VO2, MoO3, (La0.6Sr0.4)CoO3) and their improved synthetic process by nano-amorphization for applications in thermochromism and oxygen evolution reaction catalysts is discussed. Chapter 2 demonstrates low cost and large scale production of VO2 nanoparticles by bead-milling and high-throughput roll-to-roll fabrication of flexible infrared thermochromic coatings Chapter 3 introduces a new strategy to intensify visible thermochromism of layered oxides by selective coupling of intra-layer phonon modes in α-MoO3. Fundamental approach to reveal the roles of local structure on electronic band structure is identified to intensify the visible thermochromic properties by scrutinizing the thermal motion of phonon modes. Chapter 4 demonstrate low temperature synthesis of exsolution of cobalt nanoparticles on (La0.6Sr0.4)CoO3 using nano-amorphization by bead-milling. The structural evolution of the (La0.6Sr0.4)CoO3 due to milling and the exsolution of cobalt nanoparticles is shown. Chapter 5 introduces structural evolution of the h-BN powder due to milling as a simple and mass-scalable method to produce h-BN nanopowder. Chapter 6 summarizes the findings and suggests future research directions based on the developed methods and understanding of the inorganic nanoparticles (VO2, MoO3, (La0.6Sr0.4)CoO3, h-BN) in this dissertation.