Room Temperature Ammonia Sensors With Enhanced Sensitivity Based on CuO/Ti₃C₂Tₓ/Graphene Composites

Ammonia (NH3) is a common harmful gas, and its detection is widely used in fields such as chemical and medical industries. This article reports a CuO/Ti3C2 Tx/graphene composite structure for highly sensitive and rapid sensing of NH3 at room temperature (RT). CuO/Ti3C2Tx composite nanomaterials were prepared by hydrothermal method and then uniformly deposited onto the surface of continuous graphene films using the electrophoretic deposition method to construct a CuO/Ti3C2Tx/graphene composite structure. The NH3-sensing test results show that the CuO/Ti3C2Tx/graphene composite structure exhibits excellent NH3-sensing performance at RT and high-humidity environments. The CuO/Ti3C2Tx/graphene sensor has a response of up to 4.4% to 0.5-ppm NH3, which is four times that of graphene and three times that of Ti3C2 Tx, with a theoretical detection limit of 23 ppb. The response/recovery times are 29 and 119 s, respectively, achieving fast response and recovery. In addition, CuO/Ti3C2Tx/graphene sensors also have excellent selectivity, repeatability, and long-term stability. The synergistic effect of CuO, Ti3C2Tx, and graphene is the key to achieving highly sensitive and rapid NH3 sensing. The CuO/Ti3C2Tx/graphene composite structure studied in this work has great potential for application in the detection of trace NH3 at RT.