Low-temperature wet chemical synthesis strategy of In₂O₃ for selective detection of NO₂ down to ppb levels

Indium oxide microcubes (In₂O₃ MCs), an excellent gas sensing material, have been successfully prepared through a facile, low-temperature wet chemical synthesis method. X-ray diffraction, Raman shift, and X-ray photoelectron spectral data have supported for the formation of crystalline In₂O₃ with body-center cubic crystal structure. In addition, scanning electron microscopy images have evidenced for irregular and compact In₂O₃ MCs assembly. As-synthesized In₂O₃ MCs when applied to construct low-cost high performance chemiresistive sensors for the reliable detection of NO₂ at lower operating temperature demonstrates a remarkably high response of 1884 to 30 ppm @60 °C. The proposed solution-processed synthesis approach may show utility in constructing highly selective gas sensors for the detection of NO₂ and many more hereafter.