Effect of Pd sensitization on gas-sensing performance of vanadium pentoxide-reduced graphene oxide composite

Current work clearly demonstrates Pd sensitization on hydrothermally prepared vanadium pentoxide (V2O5) and on its composite with reduced graphene oxide (rGO) by a simple dip and dry method for NO2 gas sensing. Orthorhombic crystal structure of prepared sample was confirmed with the help of X-Ray Diffraction (XRD) technique. The presence of palladium (Pd) was confirmed by energy-dispersive spectroscopy (EDS) and X-Ray photoelectron spectroscopy (XPS), while fourier transform infra-red (FTIR) spectroscopy for functional group detection. Porous nano-structure morphology was confirmed with the help of scanning electron microscopy (SEM). Transmission electron microscopy (TEM) technique confirms presence of Pd nanoparticles (NPs) with an average diameter of similar to 20 nm. The photoluminescence (PL) peak arising at 641.75 nm gives the confirmation to the mid-gap states generated by oxygen vacancies. Finally, the gas-sensing performance of the prepared sensing material was measured with the help of a RIGOL digital multimeter. The result shows that 33.68% gas response towards 100 ppm NO2 gas at relatively low-working temperature (150 degrees C) along with considerable 47 and 592 s response/recovery time, respectively. The sensing material shows good reproducibility and high stability (Gas Response similar to 29%) even after 63 days. Hence Pd sensitized V2O5-rGO is a promising candidate for gas sensors working at relatively low working temperatures.

Automated summary

Pd sensitized V2O5-rGO prepared by a simple dip and dry method demonstrates good gas-sensing performance for NO2 gas at relatively low working temperature, with considerable response/recovery time and high stability.