Double sensitization induced interfacial effect engineering boosted triethylamine gas-sensing performances over yttrium trifluoride-modified Co3O4 mesoporous nanorods

Rare-earth fluoride materials can potentially boost the response performance of gas sensors owing to their unique carrier-regulation ability. In this study, YF3-modified mesoporous Co3O4 (Y-Co3O4-350) nanorods with large specific surface area and abundant surface defects were fabricated through the heat treatment of serine-assisted, hydrothermally synthesized products at 350 °C. The Y-Co3O4-350-based sensor exhibited optimal triethylamine (TEA) gas-sensing behavior and yielded the highest response value ((Rg − Ra)/Ra) = 93.2), with long-term stability and an appropriate response recovery time (18 s/36 s), at 170 °C. These splendid TEA-gas-sensing properties are attributed to the dual effect of morphology sensitization and electron sensitization, which together increase the adsorbed oxygen accumulated on the composite. In addition, DFT calculation finally determined the best adsorption location of TEA at the interface of Co3O4 {112} plane and YF3{111} plane, where the adsorption energy of TEA is − 0.64 eV. YF3 is therefore a promising modifier for enhancing the gas-sensitive properties of Co3O4 semiconductor-based sensors.