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

In this study, hydrothermal method was used to synthesized Ni-doped In 2 O 3 microcubes. XRD, Raman, XPS, and UV–Vis spectroscopy were used to examine additional structural, chemical, morphological, and optical characteristics of In 2 O 3 and Ni-doped In 2 O 3 . 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 NO 2 with the greatest sensor response (R g /R a =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 NO 2 . A high oxygen vacancy concentration gives more electrons to enhance NO 2 activation. Additionally, the incorporation of Ni into the In 2 O 3 structure contributes to the material's large surface area.