Fe-Mediated Tweaking of Band Bending and Activation Energy in α-MoO₃ Nano Lamella for Enhanced NO₂ Gas Detection...

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.