Mxene Ti3C2Tx derived lamellar Ti3C2Tx-TiO2-CuO heterojunction: Significantly improved ammonia sensor performance

Ammonia (NH3), as main industrial gas emissions, are extremely harmful to the human beings. So the detection of NH3 concentrations in special environments at room temperature (25 degrees C) is essential. Herein, the composite MXene Ti3C2Tx-TiO2-CuO was successfully prepared by one-step in-situ oxidation method using Cu(NO3)2.6H2O as a precursor. The morphology of Ti3- C2Tx-TiO2-CuO shows layered accordion-like structure. Ti3C2Tx-TiO2-CuO sensor exhibits improved NH3 gas sensing response of 56.9 toward 100 ppm NH3 at room temperature under ultra-violet (UV) light exposure, which is 89.8 % higher than that of pristine Ti3C2Tx material. The improved gas sensing performance is attributed to the irradiation of UV light, the retention of Ti3- C2Tx layered structure and the construction of TiO2-CuO heterojunction. Further, the possible gas sensing mechanism of the material was proposed and discussed.(c) 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Ammonia (NH3) emissions, the main industrial gas, are highly harmful to humans. Therefore, it is important to detect NH3 concentrations in special environments at room temperature (25 degrees C). In this study, a composite MXene Ti3C2Tx-TiO2-CuO with a layered accordion-like structure was successfully prepared. The Ti3C2Tx-TiO2-CuO sensor exhibited an improved NH3 gas sensing response of 56.9 towards 100 ppm NH3 at room temperature under UV light exposure, which was 89.8% higher than that of the pristine Ti3C2Tx material. The improved performance was attributed to the UV light irradiation, the retention of the Ti3C2Tx layered structure, and the construction of the TiO2-CuO heterojunction. The possible gas sensing mechanism of the material was also proposed and discussed.