Enhanced H2S gas-sensing properties of Pt-functionalized In2Ge2O7 nanowires

In₂Ge₂O₇ one-dimensional (1D) nanostructures were synthesized using an evaporation technique. The morphology, crystal structure, and sensing properties of the In₂Ge₂O₇ nanostructures functionalized with Pt to H₂S gas at 100 ^°C were examined. The diameters and lengths of the 1D nanostructures were a few tens of nanometers and up to a few hundreds of micrometers, respectively. Pt nanoparticles with diameters of a few tens of nanometers were distributed over the In₂Ge₂O₇ nanowires. Gas sensors fabricated from the multiple networked In₂Ge₂O₇ nanowires functionalized with Pt exhibited enhanced electrical responses to H₂S gas compared to the uncoated In₂Ge₂O₇ nanowires. The responses of the nanowires were improved 240, 234, and 225 fold at H₂S concentrations of 10, 25, and 50 ppm, respectively. The enhanced electrical response of the Pt-functionalized In₂Ge₂O₇ nanowire sensor to H₂S gas can be attributed to a combination of the spillover effect and the enhanced chemisorption, as well as the dissociation of the gas.