Facile synthesis of In2O3 nanoparticles with high response to formaldehyde at low temperature

In2O3 nanoparticles with uniform particle size (10-25 nm) were obtained using the facile precipitation strategy at room temperature with following calcined treatment. The gas-sensing performance of In2O3 nanoparticles with different calcined temperatures was investigated. The results demonstrated that the In2O3 nanoparticles calcined at 500 degrees C exhibited highest sensing response (R-a/R-g = 68.1) to 10 ppm HCHO at 100 degrees C with good selectivity, stability, reproducibility, and ultra-low limit of detection (1 ppm). The results of XPS, UV, and other characterizations indicated that In2O3-500 possessed the most absorbed oxygen species, the highest carrier mobility, and lowest band gap energies. Our work offers new insights into the development of sensing materials to the detection of volatile organic compounds (VOCs).