Enhanced n-butanol sensing performance of SnO2-based gas sensors by doping In2O3 via co-precipitation method

A series of In2O3-SnO2 nanocomposites were synthesized with a facile hydrothermal co-precipitation method and calcination after-treatment at 400 °C. The crystal phase structure, morphology, and elemental composition were characterized by X-ray powder diffraction and field emission scanning electron microscopy with energy dispersive spectroscopy. In2O3-SnO2 nanocomposite-based gas sensors were fabricated, and their potential applications were assessed by testing gas-sensing properties systematically. The results exhibited that a small amount of In2O3 dopant improved the dispersion and increased the specific surface area of SnO2 nanomaterials. Besides, the gas response towards n-butanol gas was promoted and the working temperature was decreased by doping In2O3. In particular, the 1.5 %In2O3-SnO2 nanocomposites-based sensor showed an excellent response of 76.5 towards 50 ppm n-butanol gas at 140 °C. The binding energies of the Sn 3d in nanocomposites varied with the changed doping dosage of In through XPS analysis. The enhanced n-butanol sensing performance of the fabricated In2O3-SnO2 sensors at low operating temperature may be due to a synergistic effect between In2O3 and SnO2.