Preparation of nickel oxide nanostructure by hydrothermal method as H2S gas sensor

Abstract

Gas sensing is beneficial for controlling industrial and vehicle exhaust, house articles security, and environmental management. CO₂, H₂S, SO₂, CO, H₂, O₂, and various gases are recognized by different tools. In the present research work, the undoped NiO nanoparticles were synthesized using a hydrothermal technique. The effect of heating time in a Teflon-lined autoclave on the structural, electrical, and gas sensing properties of NiO nanoparticles (NiO NPs) was investigated. The time taken for samples S1, S2, S3, and S4 are 12, 24, 36 and 48 h, respectively. The thick films of NiO were developed on a glass substrate using a screen-printing technique. The gas sensitivity using thick films was reported. The obtained NiO NPs were examined by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and EDX. The gas response of NiO thick films was tested to recognize various air pollutants, including NO₂, H₂S, C₂H₅OH, NH₃, and LPG. Among these selected gases, NiO films show the highest gas response at 250 °C for H₂S to sample 4. The maximum sensitivity was recorded at 72.14% at 250 °C. The films also shows the fast response and recovery time.