NO2 sensing behavior of Ni-doped In2O3 microcubes based chemiresistive gas sensors

In this study, hydrothermal method was used to synthesized Ni-doped In2O3 microcubes. XRD, Raman, XPS, and UV–Vis spectroscopy were used to examine additional structural, chemical, morphological, and optical characteristics of In2O3 and Ni-doped In2O3. In addition, the gas sensing measurement of synthesized material was also carried out. It was observed that the Ni-In7 sensor responds to 1 ppm NO2 with the greatest sensor response (Rg/Ra=6.46) and fastest response/ recovery time (30/120s) at 120 °C operating temperature which is 6 times greater than the Ni-In0 sensor. Furthermore, Ni-In7 displayed good stability in addition to its outstanding selectivity towards NO2. A high oxygen vacancy concentration gives more electrons to enhance NO2 activation. Additionally, the incorporation of Ni into the In2O3 structure contributes to the material's large surface area.