基于CoFe_2O_4表面催化发光的硫化铵气体传感器研究

Ammonium Sulfide Gas Sensor Based on Cataluminescence Emission on the Surface of CoFe_2O_4

基于铁酸钴(CoFe2O4)纳米材料催化硫化铵的氧化反应产生化学发光的现象,建立了一种检测空气中痕量硫化铵的催化发光气体传感器.在对合成的3种材料的催化发光性质进行比较的基础上,对分析方法条件进行了优化,其结果表明:在检测波长400 nm、反应温度306℃、载气流速400 mL/min的最优条件下,可测定的硫化铵浓度的线性范围为0.13～13 mg/L(r=0.9951,n=9),检出限为0.04 mg/L(3σ),对1.3 mg/L的硫化铵连续平行测定8次,其相对标准偏差为1.8%.此外,考察了相同浓度的常见挥发性有机物的干扰情况,其结果表明该传感器具有很好的选择性.连续60 h通过1.3 mg/L的硫化铵,发光强度无明显降低,相对标准偏差小于5%,表明此传感器使用寿命长.并将该传感器成功用于人工合成样品的分析,回收率为94.7%～103.9%.

On the basis of cataluminescence（CTL） emission on the surface of CoFe2O4 nanomaterial,a novel and sensitive sensor for the determination of ammonium sulfide was developed.The CTL characteristics and the optimal conditions including three nanomaterials morphology,air flow rate,working temperature and wavelength were investigated.Under the optimized conditions,the linear range of CTL intensity versus concentration of ammonium sulfide was 0.13～13 mg/L（r=0.9951,n=9） with a detection limit of 0.04 mg/L（3σ）.The relative standard deviation（RSD） for 1.3 mg/L ammonium sulfide was 1.8%（n=8）.Interference experiments showed that there was no response from common foreign substances,and the present sensor can be used for the continuous determination of 1.3 mg/L ammonium sulfide more than 60 h over two weeks with a RSD of less than 5%.Meanwhile,this sensor was successfully applied to determine ammonium sulfide in artificial samples with recoveries from 94.7% to 103.9%.