Fe‐Mediated Tweaking of Band Bending and Activation Energy in α‐MoO₃ Nano Lamella for Enhanced NO₂ Gas Detection Under Low Operating Temperature

Abstract

Concern over increasing pollution and ways to mitigate it is in high demand due to the swift advancement of technology and the creation of advanced utilities. Nitrogen oxide (NO2) is a well‐known evolved toxin that poses a threat to human health, the environment, and biodiversity. Therefore, several works are carried to sense the NO2 gas at its trace concentration. However, the majority of NO2 sensors that have been reported have inadequate Limit of Detection (LOD), high operating temperature, and low sensitivity. Orthorhombic molybdenum oxide (α‐MoO3) recently emerged as hotspot in the gas sensing research and noted for its high sensitivity, and distinct sensing capabilities owing to its unique layered structure. In this study, Fe‐doped α‐MoO3 nanosheets for NO2 sensing is prepared, and at a low operating temperature of 110 °C, an excellent sensitivity of 1282% for 10 ppm of NO2 is achieved. Long‐term stability, good repeatability, and an ultra‐low detection limit of 79 ppt are also demonstrated by the manufactured sensors. In addition, the obtained low activation energy of ‐2.9 KJ mol−1 and the high band bending for FM6 supports the highly responsive NO2 detection at low operating temperatures.