Room-temperature NO 2 sensing performance of ZnO/Ti 3 C 2 T x heterojunctions

In recent years, metallic Ti 3 C 2 T x MXenes have garnered considerable attention in the realm of gas sensors owing to their distinctive characteristics, including high conductivity, inherent hydrophilicity, and abundant surface termination groups. Nonetheless, Ti 3 C 2 T x -based sensing composites encounter challenges related to response/recovery time and low sensitivity, thereby limiting their applicability across diverse environmental conditions. Addressing these limitations, we present the synthesis of ZnO/Ti 3 C 2 T x nanocomposites via a facile method for gas sensing applications. The optimized composite exhibits a notable response of around 6.1% to 5 ppm NO 2 , coupled with remarkable selectivity at ambient temperatures. Moreover, the sensor demonstrates exceptional reproducibility across multiple testing iterations. The observed enhancement in gas sensing performance is attributed to the abundance of oxygen vacancies and surface functional groups within the ZnO/Ti 3 C 2 T x composites, which facilitate robust interactions with NO 2 molecules. These findings underscore the efficacy of ZnO/Ti 3 C 2 T x nanocomposites as a viable strategy for enhancing the gas sensing properties of Ti 3 C 2 T x -based sensors.