Pt Single Atom-Induced Activation Energy and Adsorption Enhancement for an Ultrasensitive ppb-Level Methanol Gas Sensor

As an important organic chemical raw material, methanol is used in various industries but is harmful to human health. Developing an effective and accurate detection device for methanol is an urgent need. Herein, we demonstrate a novel gas-sensing material with a Pt single atom supported on a porous Ag-LaFeO₃@ZnO core-shell sphere (Ag-LaFeO₃@ZnO-Pt) with a high specific surface area (192.08 m²·g^-1). Based on this, the surface activity of the Ag-LaFeO₃@ZnO-Pt gas sensor is enhanced obviously, which improved the working temperature and detection limit for methanol gas. Consequently, this sensor possesses an ultrahigh sensitivity of 453.02 for 5 ppm methanol gas at a working temperature of 86 °C and maintains a high sensitivity of 21.25 even at a concentration as low as 62 ppb. The sensitivity of Ag-LaFeO₃@ZnO-Pt to methanol gas is increased by 6.69 times compared with the Ag-LaFeO₃@ZnO core-shell sphere (Ag-LaFeO₃@ZnO). Additionally, the minimum detection limit is found to be 3.27 ppb. Detailed theoretical calculations revealed that the unoccupied 5d state of Pt single atoms increases the adsorption and activation energy of methanol and oxygen, which facilities methanol gas-sensing performance. This work will provide a novel strategy to design high-performance gas-sensing materials.