| Hydrazine(N2H4)is a colorless,pungent odor,highly toxic and carcinogenic compound.Its low-temperature and highly sensitive detection is of great significance for production safety and human health.In this thesis,Ni O hierarchical nanorods,2D porous lotus root slice-shaped Ni O and Cu-Ni O nanomaterials were synthesized by one-step solvothermal method and subsequent calcination process.The materials were assembled into gas sensors to detect N2H4.This thesis is mainly divided into the following three sections:(1)The Ni O precursor hierarchical nanorods assembled by regular arrangement of nanoparticles were synthesized by solvothermal method using Ni(NO3)2·6H2O as nickel source,water and ethylene glycol as solvent and oxalic acid as precipitant.The Ni O nanorods calcined at 700 oC have good gas-sensing performance to N2H4 at a lower operating temperature of 92 oC,with the detection limit as low as 5 ppb,and exhibits good selectivity,reproducibility and long-term stability.(2)Using Ni(NO3)2·6H2O as nickel source,water as solvent and ammonia water as precipitant,2D porous lotus root slice-shaped Ni O were synthesized by ionic liquid-assisted hydrothermal method with 1-hexadecyl-3-methylimidazole chloride,and the crystallinity and pore size of the sensitive materials were adjusted by controlling the calcination temperature to the precursors.The response value of Ni O calcined at 700 oC to 100 ppm N2H4 at 92 oC was improved to 107.6,and the recovery time was shortened to 29.6 s.In addition,the sensing mechanism of material interaction with N2H4 was analyzed by XPS and GC-MS techniques.(3)The Cu-Ni O material synthesized by extending the reaction system of pure Ni O nanosheets synthesized in the second part and adding Cu(NO3)2·3H2O as the copper source achieved improved response values to N2H4,with rapid recovery time and low operating temperature.The prepared sensor has a response value of 124.3 to 100 ppm N2H4 at a low temperature of 50 oC,and a recovery time of 15.2 s.The sensitization mechanism of the materials was analyzed by XPS and UV-Vis DRS techniques. |
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