In this paper, pure and Ag-doped SnO₂ nanospheres were synthesized by hydrothermal method and characterized via X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectra (XPS), respectively. The gas sensing performance of the pure, 1 at.%, 3 at.%, and 5 at.% Ag-doped SnO₂ sensing devices toward hydrogen (H₂) were systematically evaluated. The results indicated that compared with pure SnO₂ nanospheres, Ag-doped SnO₂ nanospheres could not only decrease the optimum working temperature but also significantly improve H₂ sensing such as higher gas response and faster response-recovery. Among all the samples, the 3 at.% Ag-doped SnO₂ showed the highest response 39 to 100 μL/L H₂ at 300 °C. Moreover, its gas sensing mechanism was discussed, and the results will provide reference and theoretical guidance for the development of high-performance SnO₂-based H₂ sensing devices.
Keywords: Ag doping; H2 sensing device; SnO2 nanospheres; synthesis and characterization.