Highly sensitive, humidity-tolerant and flexible NO2 sensors based on nanoplate Bi2Se3 film

Recently, two-dimension (2D) materials have fueled considerable interest in the field of gas sensing to cope urgent demands at specific scenarios. Unfortunately, the susceptibility to ambient humidity, and/or fragile operation stability always frustrate their further practicability. To overcome these drawbacks, we proposed one novel flexible gas sensor based on bismuth selenide (Bi2Se3) nanoplates for sensitive NO2 detection at room temperature. The as-prepared Bi2Se3 sensor exhibited favorable sensing performance, including remarkable NO2 selectivity, high response of 120% and fast response time of 81 s toward 5 ppm NO2, an ultralow detection limit of 100 ppb, and nice stability. Besides, the excellent humidity tolerance and mechanical flexibility endowed Bi2Se3 sensors with admirable reliability under harsh working conditions. The first-principles calculation further revealed the insights of extraordinary NO2 selectivity and the underlying gas-sensing mechanism.