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The gas sensitivity of semiconductor metal oxides, such as γ-Fe₂O₃ and SnO₂, is investigated together with the synergistic effects in conjunction with grapheme. Nanoparticles of γ-Fe₂O₃, γ-Fe₂O₃/SnO₂, and γ-Fe₂O₃/SnO₂/RGO, prepared by two-step fabrication, were assembled in gas-sensing devices to assess their sensitivities; response and recovery times for the detection of ethanol, methanol, isopropanol, formaldehyde, H₂S, CO, and NO gases at different temperatures but constant concentrations of 100 particles per million (ppm); and H₂S, which underwent the dynamic gas sensitivity test in different concentrations. Each sample’s crystallinity and microscopic morphology was investigated with X-ray diffraction and a scanning electron microscope. In comparative gas sensitivity measurements, the ternary composite of γ-Fe₂O₃/SnO₂/RGO was identified as an ideal candidate, as it responds to all four tested liquids in the gas phase as well as H₂S with a response value equal to 162.6. Further, only the ternary composite γ-Fe₂O₃/SnO₂/RGO hybrid nanoparticles responded to NO gas with a sensor response value equal to 4.09 in 12 s. However, only the binary composite γ-Fe₂O₃/SnO₂ responded to CO with a corresponding sensitivity of 1.59 units in 7 s.