Improved selective and sensitive detection of ethanol vapour by chemically synthesized cubic-shaped PbS/ZnO core/shell nanocomposite embedded in PVA matrix

In this work, we have reported the synthesis of PbS and PbS/ZnO core/shell nano-cubes embedded in PVA matrix and their sensing towards Ethanol gas/vapour. The prepared products were characterized by UV-vis Spectroscopy, PL Spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive Analysis of X-rays (EDAX), Transmission Electron Microscopy (TEM) and Thermo-Gravimetric Analysis (TGA). The main elements like Pb, S, Zn and O appeared in the EDAX analysis. Both the PVA/PbS and PVA/PbS/ZnO nanocomposite particles are in the nano range with an average diameter in the range 20–25 nm and 40–50 nm respectively. Thermo gravimetric analysis (TGA) clearly indicated the increase in thermal stability of PbS/ZnO core/shell nanocomposite in comparison to the bare PbS core sample. Gas sensing of PbS/ZnO core/shell nanocomposite is studied thoroughly and its sensitivity is compared with the core. A total of five (05) gases including ammonia, methanol, acetone, formaldehyde and ethanol are taken for the investigation of the fabricated sensor and it is witnessed that the sensor is more selective towards ethanol. The maximum gas response recorded was 96.411% for the core/shell composite sensor, when exposed to 700 ppm of C₂H₅OH. The experiments were carried out at room temperature. The response and recovery times of the core/shell sample were observed to decrease significantly in comparison to the core sample.