Synthesis and insights into the gas sensing mechanisms of N-doped MoS2 hierarchical structures with superior gas sensing properties at room temperature

An N-doped MoS2 hierarchical structure with outstanding gas sensing performance has been successfully synthesized by a simple in situ atomic substitution technology for the detection of NO2. N doping significantly changes the electronic properties of the MoS2 samples, reduces the charge transfer resistance and band gap. The responses of the 1.0 at% N-doped MoS2 (N-MoS2–0.1) sensor to 50 and 100 ppm NO2 at 25 °C are as high as 1603 % and 1987 %, respectively, which are respective 5.7 and 4.6 times that of the MoS2 sensor. The sensor also possesses ppt-level theoretical detection limit (270 ppt), high selectivity, long-term stability. The possible gas sensing mechanisms have been discussed in detail. This study provides a feasible solution for the synthesis of N-doped 2D materials and demonstrates the enormous development potential in the field of room temperature gas sensors.