Ce掺杂纳米WO_3的制备及其气敏性能研究

Preparation and gas-sensing properties of Ce-doped WO_3 nano-materials

在乙醇和水溶液体系中,以钨酸铵和硝酸铈为原料采用溶胶-凝胶法制得纳米级Ce掺杂的WO3粉体。用XRD测试了纳米颗粒的晶相和晶体结构,发现掺杂少量Ce的WO3粉体晶型单一,结晶度增强。用扫描电镜和比表面测试仪表征了WO3基纳米粉体。用TG-DTA测试5%Ce+WO3干凝胶,结果表明所制备的含吸附水和有机物的5%Ce+WO3纳米颗粒在450℃下反应完全。纯WO3和Ce掺杂的WO3厚膜元件对H2S有很好的灵敏度和选择性。与纯WO3元件相比,掺杂Ce的WO3元件在相对湿度RH=20%～70%有好的抗湿能力,稳定性增强。

Ce-doped WO3 nanoparticles were synthesized by sol-gel method starting from ammonium tungstate hydrate,cerous nitrate,alcohol,ammonia and nitric acid. The crystal structure and phase of the nanoparticles were characterized by XRD. The results shows a small number of doping Ce can get a single crystal and enhance crystallinity. The morphology of nanoparticles was characterized by scanning electrons microscope and BET. The thermal decomposition behavior of the 5%Ce＋WO3 xerogel was investigated by TG-DTA. The results show that as-synthesized nanoparticles contain the adsorbed water and some organic compounds below 450℃. Pure WO3 and Ce-doped WO3 thick film sensors were prepared and tested for specific sensitivity to H2S. Compared to the pure WO3 sensor,Ce-doped WO3 sensors have better ability of anti-humidity during the relative humidity RH=20%-70%.