Preparation and characterization of hollow spherical indium tin oxide with micro size by template assisted hydrothermal method

Indium tin oxide (ITO), a critical n-type semiconductor material, has widely used in the field of photoelectric material due to its significant conductivity and transparency. In addition, it also has excellent gas sensitivity. In this paper, a unique ITO, hollow spherical ITO powders were prepared by hydrothermal method using PEG-4000 & DL-aspartic acid (DLAA) and PEG-400 & ethylene diamine tetra acetic acid (EDTA) as two composite templates. The preparation conditions of the hollow spherical ITO powders with 2.2 μm diameter were obtained: the precipitator is urea, the molar ratio of DLAA and In³⁺ is 3:1, the temperature of hydrothermal reaction is 120 °C, the time of hydrothermal reaction is 10 h, the molar ratio of PEG-4000 and In³⁺ is 5:1, the temperature and time of calcination is 450 °C and 3 h respectively. Ultimately, hollow spherical ITO powders were prepared and the resulting samples were analyzed for a range of properties. The properties showed as follow: the specific surface area was 64.107 g/m², the resistivity is 164.03 Ω.cm. The formation mechanism of the hollow spherical ITO powders was discussed systematically. Significantly, unique ITO powders with hollow spherical have been obtained by template method, which has application potential in the gas sensitivity of ITO powders.