Humidity-resistant ammonia sensor based on PTFE/ZnO/Ti₃C₂T_x composite films

The development of moisture-resistant room-temperature gas sensors based on semiconductor functional materials has always been a hot and difficult research topic in the field of gas sensors. Considering the high sensitivity and stability of metal oxide semiconductor, the room-temperature gas-sensing behaviors of MXene (Ti₃C₂T_x) and the hydrophobicity of polytetrafluoroethylene (PTFE), the PTFE/ZnO/MXene composite films were prepared by depositing the PTFE and ZnO layers orderly onto the MXene film surface via a magnetron sputtering method, followed by the construction of the gas sensors based on the composite films. The PTFE/ZnO/MXene composite films were characterized by SEM, TEM and XPS, and the gas-sensing and humidity-resistant properties of the composite films-based gas sensors were investigated. Results show that the PTFE/ZnO/Ti₃C₂T_x composite films-based gas sensors exhibite good selectivity, high sensitivity, and excellent reproducibility towards ammonia at room temperature. With the increase of the thickness of the PTFE layers, the humidity resistance of the composite films-based gas sensors gradually increases, but at the cost of sensitivity.