Ni掺杂SnO_2的光谱特性及气敏性能研究

Spectroscopic Analysis and Gas Sensing Performance of Ni-doped SnO_2

采用溶剂热法将Ni掺杂到纳米SnO2中,分别利用TEM、EDAX、XRD、Raman和XPS表征了Ni掺杂后SnO2的微观形貌、结构和元素组成特征,分析了Ni掺杂对增强SnO2气敏性能的作用机理。实验结果表明,Ni的掺杂可抑制SnO2晶粒增长,减小SnO2晶粒尺寸,进而提升传感器的气敏性能。少量的Ni掺杂能够使Ni2+进入SnO2晶格中取代Sn4+产生氧空位,促进SnO2气敏性能的提高;而当Ni掺杂量达到30%时,会导致部分Ni以其他的形式存在于SnO2晶体表面上,降低SnO2气敏性能。

Ni-doped SnO2 powders were prepared by the solvethermal method. The morphology, structure and elemental composition of Ni-doped Sn O2 were characterized by TEM, EDAX, XRD, Raman and XPS. Gas sensing properties of Ni-doped SnO2 were also investigated by sensitivity measurements. The results show that Ni doping inhibits the grain growth of SnO2 and decreases the grain size, thus enhancing the gas sensitivity of SnO2. Oxygen vacancies formed by the substitution of Ni2＋ for Sn4＋ in the SnO2 matrix improves the gas sensing performance at low level of Ni doping. However, when Ni concentration reaches 30 wt%, the addition of Ni to SnO2 decreases gas sensitivity, which is attributed to the counteraction of the n- and p-type sensors.