Flexible MoS2-ZnO Nanocomposite Film for Highly Sensitive and Wide-Range NO2 Detection at Room Temperature via Heterojunction-Controlled Conduction

Abstract The development of next-generation gas-sensing devices hinges on the rational design of materials capable of delivering high sensitivity, precise selectivity, and consistent performance under realistic operating environments. With the growing demand for flexible and wearable electronics, the room-temperature operation of the sensor has become increasingly critical. Moreover, real-time monitoring in dynamic environments requires sensors with rapid response and recovery, along with the ability to detect target gases across a wide concentration range, from trace amounts that allow for early intervention to higher concentrations indicative of hazardous conditions. Herein, we report a MoS2-ZnO nanocomposite meticulously designed for the efficient detection of NO2 gas. The resulting nanocomposite exhibits a high response of 78 toward 100 ppm NO2 at room temperature, along with rapid response and recovery times of 13 s and 28 s, respectively. It further demonstrates excellent detection capability across a wide concentration range (0.4−100 ppm) and retains stable functionality under applied strain, underscoring its structural robustness and mechanical resilience. The critical role of the MoS2-ZnO heterojunction in sensing performance is comprehensively investigated in the present study using experimental characterizations and DFT simulations to elucidate the underlying mechanism responsible for the enhanced response.