Large-scale synthesis of ITO nanoparticles in an alcohol system assisted by acids

Abstract

Co-precipitation of indium and tin salts in aqueous media followed by heat treatment of the products provides a versatile route to obtain tin-doped indium oxide (ITO) nanopowders in large quantities. However, the high temperature treatment that is needed to obtain well-crystallized powders provokes particle growth through sintering and leads to poor dispersibility. In this study, ITO nanoparticles (NPs) were obtained by dehydration of the (In, Sn) hydroxide precursor and subsequent crystallization of the same in acidified 2-octanol solution under atmospheric conditions and at low reaction temperature, 180 °C. This process yields grams of well-dispersed ITO nanoparticles with an average size of ∼5 nm and a tin content of ∼10%. In addition, pellets made of ITO nanoparticles and annealed at 200 °C under vacuum exhibited a conductivity of 1.3 Ω cm.