水热法合成In2O3多孔纳米片及其甲醛气敏性能研究

Hydrothermal Synthesis and Formaldehyde Gas Sensitive Performance of Porous In2O3 Nanosheets

采用水热法合成了In2O3多孔纳米片,研究了不同溶剂以及不同反应时间对材料形貌的影响,并探讨了纳米片的晶体生长机理。将In2O3多孔纳米片制备成旁热式半导体传感器,研究了甲醛气体的敏感性能。采用XRD、SEM对合成样品的物相和微观形貌进行了分析表征,研究结果表明,随着反应时间的增加,材料发生了相变,反应时间达到24 h时,形成了多孔、尺寸约1μm、厚度约50 nm的六方相片状产物。气敏性能研究表明,在加热温度为330℃时,传感器对50ppm甲醛的灵敏度达到8,响应时间和恢复时间分别为14 s和5 s,材料存在多孔结构,气体能够进行较快的吸脱附。该传感器可检测到最低浓度为1 ppm的甲醛,且其对1-100 ppm甲醛具有良好的线性关系。

Porous In2O3 nanosheets were synthesized by using a hydrothermal method.The effects of the type of solvent and the reaction time on morphology of the materials were studied,while the crystal growth mechanism of the nanosheets was discussed.Sensitive performance of the porous In2O3 nanosheets in the form of parathermal semiconductor sensor to formaldehyde gas was studied.Phase composition and morphology of the samples were characterized by using XRD and SEM.It was observed that the material underwent a phase change as the reaction time was gradually increased.After reaction for 24 h,porous In2O3 with hexagonal crystal structure was formed.The average lateral size and thickness of the nanosheets were about 1μm and 50 nm,respectively.The In2O3-based sensor exhibited a sensitivity of 8 to 50 ppm formaldehyde at 330℃,with response time and recovery time of 14 s and 5 s,respectively.Due to the porous structure of the material,the formaldehyde gas molecules can be adsorbed and desorbed quickly.The lowest concentration of formaldehyde that could be detected by the sensor was 1 ppm,while the sensor had a linear sensitivity over the formaldehyde concentration range of 1-100 ppm.