Hydrothermal synthesis of Pd-doped rGO/ZnO-SnO2 nanocomposites for efficient hydrogen detection

By modifying the ZnO-SnO2 matrix nanocomposite material with reduced graphene oxide and doping with palladium nanoparticles, a hydrogen gas-sensitive material with p-n–n heterojunction is synthesized. At the same time, it has developed its sensing characteristics for ppm level hydrogen. ZnO nanosheets were synthesized using a simple hydrothermal method, and then ZnO-SnO2 composite materials were synthesized on the basis of ZnO, and finally 3 wt% rGO was modified and Pd nanoparticles were doped. The crystal structure and structure morphology of the material were characterized by SEM, TEM, and XRD, and the results showed that the ZnO-SnO2 nanocomposite was uniformly coated on the surface of rGO. The hydrogen sensing properties of the material were studied, and the results showed that the sensor’s sensing response to 200 ppm hydrogen was about 14.9 at the optimal working temperature of 160 ℃, and the response time and recovery time were 100 s and 220 s, respectively. The sensor has high hydrogen response, specific response to hydrogen, and low operating temperature. Its excellent sensing performance is mainly attributed to the modification of rGO and the doping of Pd nanoparticles to enhance the effective transfer of electrons.