Zhenyu Wang,Peng Sun,Tianlin Yang,Yuan Gao,Xiaowei Li,Geyu Lu,Yu Du
The flower-like WO 3 structures were successfully synthesized by a simple calcination of W 18 O 49 nanowires obtained by a microwave-assisted solvothermal method . The as-prepared products were characterized by field emission scanning electron microscopy , X-ray powder diffraction, transmission electron microscopy , and nitrogen adsorption and desorption measurements. The results indicated that the building blocks of the flower-like structure were intercrossing single crystalline WO 3 nanorods with diameter of about 30–40 nm and length of about 300–400 nm. The gas sensing properties of as-prepared products to NO 2 and acetone were investigated. It was found that the sensor based on WO 3 nanostructures exhibited excellent selectivity and high sensitivity toward NO 2 at optimum temperature of 90 °C, giving a response of about 42 to 40 ppb NO 2 . Significantly, operating at 300 °C, the sensor's response and recovery time to 100 ppm acetone was only 1 s and 6 s, respectively.
Bimetallic nanocrystals (NCs) have received a lot of attention due to its excellent catalytic performance. Here, PtRu NCs were successfully synthesized by ethylene glycol and used to modify flower-like WO 3 which was prepared via a simple hydrothermal method . The morphology and structure of the as-synthesized materials were characterized, and the performance of the gas sensor based on PtRu NCs decorated WO 3 was carefully studied. The gas sensing investigation showed that there was a significant improvement in response after PtRu NCs being introduced. Among all samples, the WO 3 sample modified with 0.4 wt% PtRu NCs showed the highest response to xylene at 170 °C (Ra/Rg = 261), which is almost 75 times than that of pristine WO 3 . In addition, it also presented fast response speed (2 s), good selectivity to xylene and excellent repeatability. The possible sensitization mechanism was proposed, the improvement of sensing performance could be ascribed to the high catalytic activity of PtRu NCs, and the regulation of depletion layer by Schottky barrier and heterojunction at the contact interface between WO 3 and PtRu NCs. This work can be promising for rapid detection of xylene for environmental protection at low temperature.
危险品化学品经营许可证（带存储）