Au decorated WO3-SnO2 nanocomposite for enhanced benzene vapors sensing performance

In this present work, we synthesized WO3-SnO2 and Au decorated WO3-SnO2 nanocomposite by hydrothermal method. The optical characterization has been done by UV/Vis spectroscopy to determine the band gap (Eg) of pure and gold (Au) decorated WO3-SnO2 which shows a reduction in Eg value from 3.56 to 3.03 eV after addition of Au in WO3-SnO2 which improves the crystallinity of WO3-SnO2 . Fourier transformed Infra red (FTIR) spectroscopy has been used to confirm the chemical bonding between Au and WO3-SnO2 nanocomposite. The x-ray Diffraction (XRD) technique was used to study the structural aspects of prepared materials which shows the decrease in crystallite size from 8 to 6.7 nm after addition of Au in pure sample. Field Emission Scanning Electron Microscopy (FESEM) has been used to investigate morphological characteristics of as prepared nanocomposite. The doping of Au was further confirmed by Energy-Dispersive x-ray spectroscopy (EDS) technique. The sensing properties have been studied from the I-V measurement of WO3-SnO2/Au nanocomposite for Benzene. The sensing parameters such as sensitivity (response), operating temperature and response and recovery time were calculated for benzene vapors. The addition of Au in WO3-SnO2 increases its response to 2.7 times for 100 ppm benzene with a reduction in response/recovery time from 18/50 s to 13/29 s. The operating temperature was 300 degrees C. Further, the material is highly selective for benzene as compared to cyclohexane, toluene and aniline.

Automated summary

In this study, WO3-SnO2 and Au decorated WO3-SnO2 nanocomposite were synthesized by hydrothermal method. Optical characterization revealed a reduction in band gap (Eg) from 3.56 to 3.03 eV after adding Au to WO3-SnO2, indicating improved crystallinity. FTIR spectroscopy confirmed the chemical bonding between Au and WO3-SnO2. XRD analysis showed a decrease in crystallite size from 8 to 6.7 nm with Au addition. FESEM was used to investigate the morphology, while EDS confirmed the doping of Au. The sensing properties of WO3-SnO2/Au nanocomposite for Benzene were studied, showing increased sensitivity and reduced response/recovery time with Au addition. The material exhibited high selectivity for benzene compared to other compounds.