Novel Sensing polymeric Nano-composite materials for CO₂ Gas Detection

Polyaniline (PANI)/zirconium vanadate (Zr–V) hybrid nanomaterials were successfully synthesized via a sol–gel-assisted polymerization method. The resulting nanohybrid was characterized using different physicochemical characterization techniques to identify the morphological, crystalline, and chemical structures using scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Thermal Gravimetric Analysis (TGA). An optimal composition of 1 PANI: 1.5 Zr–V was obtained using the first synthesis route. The nanohybrid exhibited a highly crystalline structure with a branched nanotubular morphology resembling cauliflower. An electrospun composite nanofiber matrix was fabricated by incorporating the optimized PANI/Zr–V nanocomposite into a polyvinyl alcohol (PVA) matrix. Electrospinning parameters, including flow rate, tip-to-collector distance, and applied voltage, were optimized to produce uniform nanofibers. The CO₂ sensing performance of the composite nanofibers was evaluated as a function of temperature by measuring changes in resistance across sputtered platinum electrodes. The nanofiber matrix exhibited a rapid, high sensing response to CO2, achieving maximum response and recovery times of 22 s and 20-25 s, respectively, at 200 ℃. The maximum sensitivity for CO₂ gas recorded was 100% at 200 ℃. Overall, the superior CO₂ sensing characteristics arise from the combined effects of surface adsorption, protonation–deprotonation dynamics in PANI, interfacial charge transfer within the heterojunction, and the high surface area nanofibrous morphology.