Fast response ammonia sensors based on TiO2 and NiO nanostructured bilayer thin films

作者：Kumar Arvind; Sanger Amit; Kumar Ashwani; Chandra Ramesh^*

来源：RSC Advances, 2016, 6(81): 77636-77643.

DOI：10.1039/c6ra14342c

In the present work, we have synthesized TiO2 and NiO based bilayer nanostructured thin films on glass substrates via DC magnetron sputtering at room temperature. The structural and morphological properties of the bilayer samples were systematically studied using numerous analytical techniques, including X-ray diffraction (XRD), Raman spectroscopy, atomic force microscopy (AFM), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The ammonia (NH3) gas sensing properties of both bilayer sensors towards a low detection range (5-500 ppm) within a low operating temperature regime (30-300 degrees C) have been extensively discussed in detail. The TiO2/NiO and NiO/TiO2 sensors exhibited high sensing responses (R-g/R-a similar to 7.6) and (R-a/R-g similar to 5.0) with very fast response times (similar to 24 s) and (similar to 30 s) towards 100 ppm NH3 at 280 degrees C and 200 degrees C, respectively. Furthermore, the working principle attributed behind their good gas sensing properties was also investigated via formation of p-n and n-p heterojunctions at the interface.

• 出版日期2016