Hierarchical flower-like Bi2SiO5/MWCNT nanocomposites for highly sensitive LPG sensor at room temperature

Designing and fabricating a heterojunction pn-type semiconductor can provide significant advantages for improving the gas sensing performance. Herein, a facile and cost-effective hydrothermal method is used to synthesize a flower-like Bi2SiO5/MWCNT-x (where MWCNT is x = 0-20 wt%) nanocomposites. Structural and morphological studies of as-prepared samples are carried out by using various characterization techniques viz., X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM). The enhanced LPG sensing performance at room temperature of flower-like Bi2SiO5/MWCNT nanocomposites is reported here. A systematic investigation of Bi2SiO5/MWCNT nanocomposites demonstrates that 10 wt% content Bi2SiO5/MWCNT nanocomposites exhibit excellent sensing properties: high sensitivity as well as selectivity towards LPG along with good reproducibility at room temperature. The Bi2SiO5/MWCNT-10 nanocomposite response towards 1500 ppm of LPG reached 77.71% at 30 degrees C (room temperature) and the response and recovery times are 21 s and 37 s respectively. The unique flower-like structure and synergetic effects are supposed to be responsible for improving the gas sensing performance of Bi2SiO5/MWCNT nanocomposites. Besides, the effect of relative humidity on the sensing performance of the Bi2SiO5/MWCNT nanocomposites is investigated. However, the as-prepared Bi2SiO5/MWCNT nanocomposites based sensor showed effective gas sensing performance at high humidity. The present sensor shows a high LPG response at room temperature and decreases with increase of temperature suggest its promising usage for the low-temperature region. This novel Bi2SiO5/MWCNT nanocomposite promises to provide an essential gas sensing material for the detection of LPG. (C) 2020 Elsevier B.V. All rights reserved.