Preparation of SnO2 nanoparticles less than 10 nm in size by precipitation using hydrophilic carbon black powder

Tin oxide powder has recently been prepared by a modified precipitation method in which the precipitate is mixed with carbon black powder, a method which offers low cost and mass production. In this study, we prepared tin oxide powder by the modified precipitation method using hydrophilic and non-hydrophilic carbon black powders. When using the hydrophilic carbon black powder, the crystallite size of the tin oxide after firing at 600 °C was 7.5 nm. In contrast, when using the non-hydrophilic carbon black powder, the crystallite size was 18 nm. Thus the crystallite size was shown to depend on the hydrophilicity of the carbon black powder. The smaller crystallite size obtained may be a result of the gel precipitate (stannic acid) particles being dispersed more uniformly on the surface of the hydrophilic carbon black powder than those on the surface of the non-hydrophilic carbon black powder.