Co3O4/rGO nanocomposite: Influence of Ag loading on liquified petroleum gas sensing detection

The effect of Ag-loading on the liquefied petroleum gas (LPG) sensing properties of 80 wt% Co 3 O 4 loaded onto rGO (Co 3 O 4 /rGO) nanocomposite was investigated. Co 3 O 4 /rGO nanocomposite was synthesized using the hydrothermal method, followed by Ag nanoparticles decorated on the surface using the precipitation method. The presence of Ag nanoparticles was confirmed by energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The Ag-loading significantly increased the sensitivity and selectivity towards LPG at low temperatures. The 0.5 wt% Ag-loaded sensor demonstrated a highly selective, and stable LPG sensing response with an exceptional sensitivity (0.016 ppm −1 ) and a low detection limit of 0.053 ppm (53 ppb) at 100 ℃. The principles underlying the gas sensing capabilities were thoroughly discussed. Ag-loading onto the Co 3 O 4 /rGO sensor's surface was responsible for the sensor's notable improvement in LPG detection. The synergetic combination of Co 3 O 4 and rGO at the p-p nanoscale heterojunction improved gas adsorption. Thus, the sensor surface developed numerous active sites, significantly aiding in the chemisorption of more LPG molecules due to the spillover effect and increasing sensitivity. • Ag-loaded Co 3 O 4 /rGO nanocomposite was synthesized using the hydrothermal method. • 0.5 wt%Ag/Co 3 O 4 /rGO showed higher sensing sensitivity and selectivity towards LPG at 100 ℃. • The sensor showed a sensitivity of 0.01529 ppm −1 and a low detection limit of 53 ppb at 100 ℃. • The sensor showed a long-term stability of 90 days towards 1000 ppm LPG.