Light-enhanced NO2 sensing performance and sensing mechanism of flower-like Cl uniformly doped In2O3

As a poisonous and harmful gas, NO 2 , is not only harmful to the environment, but also detrimental to human health. In this work, ionic liquids (1-hexadecyl-3-methylimidazolium chloride [C 16 Mim] Cl) were selected as dopants to prepare flower-like Cl uniform doped In 2 O 3 nanomaterials. The material exhibits excellent sensing performance to NO 2 under UV light because of Cl uniform doped. Compared with the experiment in dark conditions, the response value of the sensor to 5 ppm NO 2 under UV light is approximately two times higher (S = 425.9) and presents a faster recovery rate (69 s). Chlorine doping shifts the valence band of the material upwards, facilitating the photogenerated electron leap under UV illumination. Moreover, the in-situ DRIFT under UV light were employed to verify the interaction between the materials and NO 2 gas in N 2 , air and O 2 atmospheres respectively. It was found that the presence of oxygen in the environment affects the adsorption of NO 2 on the surface of the Cl doped In 2 O 3 material. This work is of great significance to the sensing mechanism investigation of photo-activated NO 2 gas sensors.