混合碱法制备Zn掺杂NiO纳米粉体及其甲醛气敏性能的研究

Preparation of Zn doped NiO nanoparticles using mixed alkali method and their Gas sensitivity of HCHO

为了制备高灵敏度、快速响应的甲醛气敏传感器材料,采用混合碱法制备了Zn掺杂Ni O纳米粉体,并对其进行SEM、XRD和气敏性能测试,研究了不同浓度Zn掺杂对Ni O纳米粉体的形貌、晶体结构及甲醛气敏性能的影响。结果表明:Zn掺杂对其结构及形貌未产生影响,Zn掺杂明显提高了Ni O纳米粉体对HCHO气体敏感性能,在Zn掺杂量为摩尔分数5%的Ni O纳米粉体对HCHO气体具有最佳的气敏特性,工作温度为300℃时,粉体对体积分数为2000×10^(-6)的HCHO气体灵敏度达到18.19,在体积分数为(50~2000)×10^(-6)的HCHO气体范围内,随着HCHO气体浓度增大,Zn掺杂Ni O纳米粉体的灵敏度呈上升趋势。这主要是由于Zn元素掺杂使Ni O的空位增多,缺陷增多,从而为气敏反应提供更多的活化点,提高了气敏性能。

To prepare materials for HCHO gas sensor with higher sensitivity and quicker response,NiO and Zn doped NiO nanoparticles were prepared by mixed alkali method.Effects of Zn doping on the HCHO gas sensitivity of NiO nanoparticles were investigated by SEM,XRD and measurement system of gas sensor.The results show that Zn doping has no influence on the structure and surface morphology of NiO nanoparticles.The HCHO gas sensitivity of NiO nanoparticles are effectively improved by Zn doping and the optimal doping concentration is mole fraction of 5%.The sensitivity is up to 18.19 for the sensors based on mole fraction of 5%Zn doped NiO nanoparticles for 2000×10-6(volume fraction)HCHO at 300℃.The sensitivity of the gas sensor gradually increases with the HCHO concentration increasing in the range of(50-2000)×10-6(volume fraction).The doped Zn is incorporated into the NiO host,which provides more gas-sensitive reaction activation point and improves the gas-sensitive properties.