Effect of hydroxy and carboxy groups on anisotropic growth of rutile-type titania under hydrothermal conditions. Issue 3 (1st September 2017)

• Record Type: Journal Article
• Authors: Kobayashi, Makoto; Lee, Sungho; Kato, Hideki; Kakihana, Masato
• Is Part Of: Journal of Asian ceramic societies. Volume 5:Issue 3(2017)
• Page Start: 320
• Page End: 325
• Publication Date: 2017-09-01
• Subjects: Rutile -- Hydrothermal -- Additives -- Nanorods -- Anisotropic growth -- Functional group effects; Ceramics -- East Asia -- Periodicals; Materials science -- Periodicals; 620.1405
• DOI: 10.1016/j.jascer.2017.06.006
• Languages: English
• ISSNs: 2187-0764

Abstract

Abstract: Control of crystal growth leads to highly functional materials with desired morphologies. In this study, the relationship between select additives and the crystal growth of rutile-type titania under hydrothermal conditions using α-hydroxy acids, carboxylic acids, or alcohols as additives was systematically investigated. Without additives, rod-like rutile crystals with average dimensions of 295 nm × 67 nm were formed. Acceleration of the crystal growth was observed and the aspect ratios of the resulting rod-like crystals were found to increase in the presence of the additives. Alcohols promoted crystal growth along the c -axis, but not in the direction to perpendicular to [001]. Carboxylic acids accelerated the overall crystal growth and this increase was more enhanced along the c -axis than that along others. Both effects were observed using α-hydroxy acids. In addition, the present results implied that the size of the hydrocarbon groups in alcohols and α-hydroxy acids appeared to be related to the acceleration of crystal growth along the c -axis. Hydroxy groups may reduce the surface energy of the crystal facets perpendicular to the c -axis by their adsorption on those facets, resulting in the formation of rod-like crystals with high aspect ratio.