Flower-like Hydroxyfluoride-Sensing Platform toward NO₂ Detection

We report for the first time using zinc hydroxyfluoride (ZnOHF) for efficient NO₂ gas detection. The prepared ZnOHF had a unique flower-like architecture self-assembled by nanorods with a diameter of 150 nm and length of 2-3 μm. The sensing performance toward NO₂ detection indicated that the prepared ZnOHF exhibited high response (82.71), short response/recovery time (13 s/35 s) to 10 ppm of NO₂, and excellent selectivity at 200 °C, greatly outperforming the ZnO raw material. ZnOHF could work in a wide detection window ranging from 100 ppb to 50 ppm, implying its practical application prospects in both industry and daily life. The excellent sensing behavior of ZnOHF originated mainly from the negligible oxygen ions adsorbed on the material surface, which was caused by the higher work function of ZnOHF. Therefore, almost all conduction band electrons can be used in the NO₂ gas sensing.