Ionic liquid-assisted synthesis of 2D porous lotus root slice-shaped NiO nanomaterials for selective and highly sensitive detection of N2H4

The sensitive and effective detection of Hydrazine (N2H4), a highly toxic compound, has been urgently required to ensure safe manufacture and physical health. In this work, a 2D porous lotus root slice-shaped NiO material was prepared by the ionic liquid-assisted hydrothermal method of 1-hexadecyl-3-methylimidazole chloride with regulated calcination temperature, and the characterization was exclusively confirmed through TG, XRD, SEM, TEM, XPS, and other test methods. The gas-sensing test results demonstrated that the small amount of ionic liquid residues in the NiO material after being calcined at 700 °C significantly improved its gas-sensing performance to N2H4 gas. The fabricated sensor achieved a response value of 107.6–100 ppm N2H4 at an optimal working temperature of 92 °C, a recovery time of 29.6 s, with the lowest detection limit of 10 ppb. In addition, we further analyzed the sensing mechanism of NiO materials to N2H4 gas through XPS and gas chromatography-mass spectrometry.