基于WO_(3)纳米材料的乙醇气体传感器

Ethanol gas sensor based on WO_(3) nanomaterials

采用水热法以Na2WO4·2H2O为原料、聚乙烯吡咯烷酮(Polyvinylpyrrolidone,PVP)为辅助剂合成了不同形貌的WO_(3)纳米材料。利用X-射线衍射仪(X-ray diffraction,XRD)、扫描电子显微镜(Scanning electron microscope,SEM)和傅里叶变换红外光谱仪(Fourier transform infrared,FT-IR)对WO_(3)进行了表征,并研究了添加PVP对WO_(3)气敏性能的影响。结果表明,添加不同量的PVP,不仅可以使WO_(3)的形貌和微观结构发生改变,还可以优化WO_(3)传感器的乙醇气敏性能。其中,添加PVP 7.5%(质量比)辅助合成的WO_(3)传感器气敏性能最好,在最佳工作温度300℃下对300 ppm浓度的乙醇灵敏度高达124.2,同时,还表现出良好的重复性和稳定性。对添加7.5%PVP合成的WO_(3)的气敏机理进行了讨论,其气敏性能的提高归因于WO_(3)纳米颗粒尺寸较小、表面缺陷较多,有利于吸附更多的乙醇气体。

WO_(3)nanomaterials with different morphologies were synthesized through a hydrothermal method using Na2WO4·2H2O as a raw material and polyvinylpyrrolidone(PVP)as an auxiliary agent.X-ray diffraction meter(XRD),scanning electron microscope(SEM),and Fourier transform infrared spectrometer(FT-IR)were used to characterize the WO_(3)products.The effect of PVP additive on the gas-sensing properties of WO_(3)was also investigated.The results showed that the PVP additive not only changed the morphology and microstructure of WO_(3)nanomaterials,but also optimized the ethanol-sensing properties of WO_(3)sensors.The WO_(3)sensor prepared with 7.5%(mass ratio)PVP showed the highest response.Especially at optimal working temperature of 300℃,the response to 300 ppm ethanol was 124.2.Moreover,the sensor also showed good repeatability and stability.The gas sensing mechanism of WO_(3)prepared with 7.5%PVP was also discussed.It was believed that the enhanced ethanol-sensing property benefited from the smaller WO_(3)nanoparticles and the more surface defects for sufficient ethanol adsorption.