Highly improved toluene gas-sensing performance of mesoporous Ag-anchored cobalt oxides nanowires

Mesoporous cobalt oxides nanowires (Co3O4 NWs) were synthesized by the nanocasting method, and then Ag nanoparticles with the different content were anchored on the surface of Co3O4 NWs. The exper-imental results indicate that Ag nanoparticles hardly affect the morphology and microstructure of Co3O4 NWs and actually exist on the surface of Co3O4 NWs. It is worth mentioning that Ag-loading greatly improves the toluene gas-sensing performance of Ag-anchored Co3O4 NWs. The operating temperature of Ag-anchored Co3O4 NWs sensors decreases from 210 degrees C for Co3O4 NWs sensor to 190 degrees C, while the response to 100 ppm toluene gas increases 3-folds. Ag0.166-Co3O4 NWs sensor exhibits the best gas -sensing performance due to the optimal Ag-loading content. Ag nanoparticles not only provide more effective oxygen adsorption sites to reduce resistance in air, but also form metal-semiconductor hetero-junctions at the Ag/Co3O4 interface to increase resistance in toluene gas. In this way, Ag-loading can fur-ther improve the gas-sensing performance of mesoporous Ag-anchored Co3O4 NWs sensors to toluene gas.(c) 2022 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.