The fabrication of PVP/NiAc nanofiber as a QCM active layer for hazardous vapor detection

The detection of hazardous vapors is crucial for controlling their pollution in the environment. The Quartz crystal microbalance (QCM) stands out as a high-performance sensing device that features high sensitivity, simplicity, low cost, and the ability to operate at room temperature. In this study, a QCM has been coated with a new active layer of PVP/NiAc composite nanofibers to detect hazardous vapor. The QCM surface is coated with PVP/NiAC nanofiber which is fabricated using the electrospinning method. The morphology and average diameter of PVP/NiAc composite nanofibers were investigated utilizing an optical microscope and ImageJ software, respectively. The developed composite nanofibers have an average diameter of 989 ± 172.61 nm. The fabricated sensor was tested against methanol, acetone, dimethylacetamide (DMAc), and formaldehyde vapors in different concentrations ranging from 5.0 to 22.5 ppm. The sensitivities of QCM sensors with PVP/NiAc nanofiber active layer were 2.35, 0.62, 0.32, and 0.29 Hz/ppm for methanol, formaldehyde, acetone, and DMAc, respectively. The developed sensor performed the highest sensitivity and frequency shift response in detecting methanol vapors. Furthermore, the adsorption phenomena were investigated by adapting several adsorption models, including Scatchard, Freundlich, Langmuir, and Langmuir–Freundlich, to validate the physical adsorption affinity. In conclusion, the QCM sensors based on PVP/NiAc composite nanofibers can be a considerable way to detect hazardous vapors, especially methanol, in various sensing applications.