Humidity sensor based on BiOBr synthesized under ambient condition

Flexible humidity sensors are effective portable devices for human respiratory monitoring. However, the current preparation of sensitive materials need harsh terms and the small production output limits their practicability. Here, we report a synthesis method of single-crystal BiOBr nanosheets under room temperature and atmospheric pressure based on a sonochemical strategy. A flexible humidity sensor enabled by BiOBr nanosheets deliver efficient sensing performance, a high humidity sensitivity (I g/I 0 = 550%) with relative humidity from 40% to 100%, an excellent selectivity, and a detection response/recovery time of 11 and 6 s, respectively. The flexible humidity sensor shows a potential application value as a wearable monitoring device for respiratory disease prevention and health monitoring.