Promotion effect of Pt on a SnO2-WO3 material for NOx sensing

作者：Wang Chen Yang; Hong Zih Siou; Wu Ren Jang^*

来源：Physica E: Low-Dimensional Systems and Nanostructures , 2015, 69: 191-197.

DOI：10.1016/j.physe.2015.01.041

• Nanocomposite
• Calcinations method
• Resistance signal
• NOx sensor

Metal-oxide nanocomposites were prepared over screen-printed gold electrodes to be used as room-temperature NOx (nitric-oxide (NO) and nitrogen dioxide (NO2)) sensors. Various weight ratios of SnO2-WO3 and Pt loadings were used for NO sensing. The sensing materials were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and BET surface analysis. The NO-sensing results indicated that SnO2-WO3 (1:2) was more effective than other materials were. The sensor response (S=resistance of N-2/resistance of NO=R-N2/R-NO) for detecting 1000 ppm of NO at room temperature was 2.6. The response time (T-90) and recovery time (TR90) was 40 s and 86 s, respectively. By further loading with 0.5% Pt, the sensor response increased to 3.3. The response and recovery times of 0.5% Pt/SnO2-WO3 (1:2) were 40 s and 206 s, respectively. The linearity of the sensor response for a NO concentration range of 10-1000 ppm was 0.9729. A mechanism involving Pt promotion of the SnO2-WO3 heterojunction was proposed for NO adsorption, surface reaction, and adsorbed NO2 desorption.

• 出版日期2015-5