Highly sensitive NO2 gas sensor based on Ag decorated ZnO nanorods

In the present work, ZnO nanorods and Ag nanoparticles (NPs) decorated ZnO nanorods (NRs) were synthesized on a Si/SiO2 substrate by a simple chemical hydrothermal route. Various characterization techniques studied phase formation, surface morphology, and elemental composition of prepared samples. Gas sensing measurements for pristine ZnO and Ag/ZnO NRs have been carried out under a low detection limit (2–10 ppm). The highly crystalline nature of NRs aided in achieving a great sensing response. The ZnO NRs exhibit a sensing response of 934% towards 10 ppm NO2 at a working temperature of 180 °C. However, Ag/ZnO sensor gives the highest sensing response of 1075% for 10 ppm NO2 at a working temperature of 180 °C. The cause behind the increment of Ag/ZnO sensor response is explained via chemical and electronic models. These observations make an energy-efficient sensor for the detection of NO2 in the environment.