TiO_2-In-Nb_2O_5敏感材料响应TMA气敏特性分析

Analysis on TiO_2-In-Nb_2O_5 Characteristics in Terms of Responding to Trimethylamine Sensitivity

以含In的TiO2为基质,与重量比为10%的Nb2O5混合,TiO2-In-Nb2O5混合敏感材料有效解决了三甲胺(TMA)动物食品测鲜气敏器件中提高电导率和保持高灵敏度之间的矛盾。并利用XRD、SEM对该混晶体的结构、形貌及其机理进行分析,发现:该富钛混晶体中颗粒间的空隙增大、颗粒颈部变细,有效提高了响应TMA敏感特性;混合过程中所形成含铌的氧化态混晶体是缺氧态的,氧空位的增多有助于敏感材料电导率的增加。

For trimethylamine（TMA）-based sensors used in creatural food freshness testing,TiO2-In-Nb2O5, a mixed sensitive material, composed of basic substance TiO2 that includes In, and 10% of Nb2O5 in weight, solves effectively a contradiction between improving the conductivity and keeping high sensitivity. It analyzes the structure,morpha and mechanism of the mixed crystalusing X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The results show that granules of the rich titanium mixed crystal have lager interspaces, and thinner cervixes. So, it can effectively improve sensitivity of responding TMA. In addition, a oxidated solute, which contains niobium and is produced in the process of composition, is in the anoxic phase. And the increase of oxide vacancies is helpful to incease the con- ductivity of the sensitive material