Effect of Ru-loading on the sensing capabilities of Co3O4/rGO for LPG detection at low temperature

Liquefied petroleum gas (LPG) production is imperative as part of the global energy mix, while its timely detection is also vital for the safety of mankind. Thus, herein, Ru-loaded Co 3 O 4 /rGO nanocomposites were evaluated for LPG sensing. Structural analyses confirmed the successful loading of Ru nanoparticles (NPs) onto Co 3 O 4 /rGO sheets, resulting in the formation of hierarchical nanostructures as observed in the morphology analysis. Among the fabricated sensors, the 1.5 wt% Ru sensor exhibited the highest sensitivity of 12.3 toward 1000 ppm LPG at 75 °C, with a rapid response time of 44 s and a recovery time of 218 s. When the sensors were tested toward LPG in the presence of other interfering gases (NO 2 , CH 4 , CO, C 3 H 8 , C 3 H 6 O, CH 3 OH, C 2 H 5 OH, and 90 % RH, the sensor demonstrated superior sensitivity, stability, and selectivity toward LPG at a low temperature of 75 °C. Moreover, the sensor demonstrated good humidity tolerance and operational stability, retaining 95 % of the initial response over 30 days. These enhancements are attributed to the catalytic role of Ru and its promotion of charge transfer at the Co 3 O 4 /rGO interface. The findings highlight the potential of Ru-decorated Co 3 O 4 /rGO as a promising material for low-temperature LPG detection. Keywords : Co 3 O 4 ; rGO; Ru; Nanoparticles; LPG; Gas sensing. • Ru-loaded Co 3 O 4 /rGO nanocomposite were successfully synthesized using the hydrothermal method. • 1.5 wt%Ru/Co 3 O 4 /rGO showed higher sensing sensitivity and selectivity towards LPG at 75 °C. • The Sensor exhibited strong humidity tolerance at low operating temperatures. • This sensor showed reliable performance for practical applications.