以葡萄糖作为碳源,采用水热法制备纳米碳球,并将其作为造孔剂制备ZnO多孔材料。分别用扫描电镜、透射电镜、X射线衍射仪、氮吸附比表面积测试仪对材料进行表征,并研究ZnO多孔材料对应元件的气敏性能。实验结果表明:添加50 m L纳米碳球制备出的ZnO多孔材料其对应元件对乙酸表现出高灵敏度和较好的选择性;在相对湿度为50%,工作温度为310℃时,该材料对应元件对体积分数为1 000×10-6乙酸的灵敏度为393.8,为纯ZnO材料的63.6倍。
Graphene （G） was prepared by reducing graphene oxide （GO） with hydrazine hydrate. SnO-graphene com- posites with different amounts of graphene were prepared via hydrothermal method. SnO-G composites were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The effects of the graphene content in the composites and the hydrothermal temperature on the gas-sensing re- sponses of the materials to formaldehyde vapor were investigated. The gas-sensing selectivity of the sensor based on SnO-1% G （100 ℃, 10 h） composite to five kinds of gases （1000 × 10^-6） was also studied. The results revealed that the sensor based on SnO-1% G （100 ℃, 10 h） exhibited high response to formal- dehyde vapor when the operating temperature of the sensor was 133 ℃ and the response to 0.001 × 10^-6 formaldehyde attained 3.9. The response time and recovery time for 0.001 × 10^-6 formaldehyde were 24 and 12 s, respectively.
Xiangfeng ChuXiaohua ZhuYongping DongWangbing ZhangLinshan Bai
Ni^（2＋）-doped ZnO nanorods with different doping concentrations are prepared via the solvothermal method.The doped ZnO nanorods are characterized by X-ray diffraction（XRD） and scanning electron microscopy （SEM）,respectively.The amount of Ni^（2＋） ions that enter the lattice of ZnO increases with increasing the Ni^（2＋）/Zn^（2＋） molar ratio when the molar ratio of Ni^（2＋）/Zn^（2＋） in the starting solution is lower than 3%and does not change obviously if the mole ratio of Ni^（2＋）/Zn^（2＋） in the starting solution is in the range of 3-10 mol%.The effect of Ni^（2＋） doping on the gas-sensing properties is investigated.The results reveal that the amount of Ni^（2＋） has a great influence on the response（R_a/R_g） and the gas-sensing selectivity.The sensor based on 1 mol%Ni^（2＋） doped ZnO nanorods （120℃,10 h） exhibits a high response to acetic acid vapor,in particular,the responses to 0.001 ppm and 0.01 ppm acetic acid vapor reach 1.6 and 2,respectively.The response time and the recovery time for 0.001 ppm acetic acid are only 4 s and 27 s,respectively.
