A room-temperature ammonia gas sensor based on the h-MoO3@Graphene composite film with fast response time

The release of ammonia (NH 3 ) in industry or daily life is harmful to human health. A gas sensor was developed using h -MoO 3 nanorods and graphene film to detect and eliminate this. The h -MoO 3 nanorods were first synthesized by chemical bath deposition using ammonium molybdate tetrahydrate (NH 4 ) 6 Mo 7 O 24 •4H 2 O and HNO 3 and then deposited on the graphene film transferred to SiO 2 /Si substrate by electrochemical bubbling method. Subsequently, gas-sensitive h -MoO 3 @Graphene composite films were prepared and analyzed using Raman, XRD, SEM, and UV–vis. The gas sensor's performance was evaluated to detect NH 3 at a room temperature concentration range of 1–60 ppm. Compared with graphene, the conductivity of the composite film with 10 mg/ml h -MoO 3 nanorods was increased by 40 % and the sensitivity increased by 10 times. The sensor h -MoO 3 @G-10 showed the best sensing performance to 1 ppm NH 3 . Sensor sensitivity, response and recovery time are 1.1 %, 46.8 s and 17.8 s.