Functionalized Titanium Carbide-Polymer Nanofiber Composites via Electrostatic Assembly for Room-Temperature SUB-PPM NO₂ Sensing

The increasing demand for low-power, high-performance gas sensors operating at room temperature has driven interest in novel nanomaterials with large surface areas and high chemical reactivity. In this study, we report the fabrication of a high-sensitivity nitrogen dioxide (NO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>) sensor based on polyvinylidene fluoride (PVDF) nanofibers functionalized with titanium carbide nanomaterial via solution based simple dip coating process. Titanium carbide nanosheets were coated onto the surface of PVDF nanofibers, resulting in titanium carbide/PVDF composites. This strategy leads to the formation of titanium carbide nanosheets coating over the polymer nanofiber network, significantly enhancing gas diffusion pathways and the density of active sites for NO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> adsorption. The sensor exhibits 5.9% response to 5 ppm NO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> at room temperature. Structural analysis confirmed the successful etching of Al from the Ti<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>AlC<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> precursor and uniform titanium carbide coating. The fabricated titanium carbide/PVDF networks exhibited linear I-V characteristics and stable operation. This work demonstrates the potential of easy and facile fabrication process for developing next-generation gas sensors based on 2D/1D hybrid materials. The resulting composite not only improves sensitivity and detection limits but also offers scalability and flexibility, making it suitable for wearable and ambient air monitoring applications. These findings provide a promising method for the development of portable, low-power, and selective NO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> sensors for environmental safety and health monitoring.