镍镧复合氧化物的掺杂及其气敏性能研究

Study on doping of La-Ni complex oxide and its gas-sensing properties

用共沉淀法制备了镍镧复合氧化物并对其进行三价、四价离子系列掺杂。研究了掺杂物的气敏性能。实验结果表明,SiO2,TiO2,SnO2,Al2O3,SbCl3等掺杂的复合氧化物,均对乙醇有较高的气敏性,而对汽油、H2及LPG等气敏性较低。其中TiO2掺杂量为4%(摩尔分数)的镍镧复合氧化物对乙醇的气敏性能最好。探讨了Si,Ti,Sn,Al,Sb等离子的价态,离子半径及复合氧化物的形成条件等与气敏性能的关系,研究了工作温度,被测气体浓度对元件气敏性能及对气体选择性的影响。

La-Ni complex oxide was synthesized by chemical copreciptation method and doped with three and four valence ion, respectively. The gassensing properties of the complex oxides have been studied.The results reveal that the complex oxide doped with SiO2,TiO2,SnO2,Al2O3,SbCl3 all show high sensitivity to ethanol and low sensitivity to petrol, H2 and LPG.The complex oxide doped with 4% TiO2(mol fraction) shows the highest sensitivity to ethanol.The relationship between valence state of ions,such as Si,Ti,Sn,Al,Sb, radius of ion, synthetic condition and the gassensing properties of the complex oxides was discussed. The effect of working temperature, concentration of tested gases on the gassensing properties and gas selectivity of elements was investigated.