Abstract

2D transition-metal carbides (Ti₃C₂Tₓ MXene) intercalated with organic molecules have been widely used in batteries and supercapacitors, but are quite rarely reported for gas sensing. Since Ti₃C₂Tₓ is sensitive to oxygen, most methods for preparing the intercalated Ti₃C₂Tₓ involve stirring the reactants with Ti₃C₂Tₓ for several hours under nitrogen protection. Herein, a method to prepare a hybrid of Ti₃C₂Tₓ and intercalated polysquaraine through microwave-assisted in situ polymerization that takes only a few minutes without the need of using a protective atmosphere is demonstrated. Owing to the increased interlayer space of the Ti₃C₂Tₓ after the polymerization, the gas sensors based on the hybrid exhibit a good sensing performance for NH3 detection, being able to detect at least 500 ppb NH₃ with a 2.2% ppm⁻¹ of sensitivity. This study provides a facile preparation method for developing intercalated MXenes, which are expected to be useful for a wide range of applications.