Cobalt doped cubic and rhombohedral In2O3: The role of crystalline phase of indium oxide in sensor response to hydrogen

Abstract

Cubic and rhombohedral indium oxide, as well as the In2O3 based composites with cobalt, were synthesized by hydrothermal method. It is shown that, regardless of the phase state of indium oxide, cobalt ions are embedded in the In2O3 structure during synthesis, resulting in the expansion of its lattice and an increase in the specific surface area of the composites. The introduction of cobalt into different phases of In2O3 changes the ratio of oxygen vacancies in composites. These findings underscore the dependence of sensor response of the composites to hydrogen on the phase state of In2O3.