Co-electrospinning polyacrylonitrile (PAN) / polymer of intrinsic microporosity-1 (PIM-1) for electrochemical-based sensor for pyridine detection and Absorption

Abstract

The electrospinning of the polymer of intrinsic microporosity-1 (PIM-1) poses challenges due to its limited solubility and tendency to form bead-like structures at high concentrations. This work details the synthesis and analysis of electrospun composite fibers made from polyacrylonitrile (PAN) and PIM-1 for electrochemical applications. The data analysis confirmed the successful incorporation of PIM-1 into the PAN matrix. The fiber characteristics were significantly influenced by PIM-1 loading (1–10%), resulting in fiber diameters ranging from 0.8 to 1.7 μm. A 10% concentration of PIM-1 results in the formation of macropores with diameters ranging from 0.5 to 1.7 μm. Optical analysis using diffuse reflectance spectroscopy (DRS) and Tauc plots indicated a decrease in the band gap from 2.2 eV for pure PIM-1 to 1.8 eV, thereby enhancing light absorption. The electrochemical performance was evaluated by cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA), demonstrating that PAN/PIM-1 fibers exhibit superior electrochemical performance. The composite fibers were later evaluated as electrodes for volatile organic compounds (VOCs), demonstrating selectivity for pyridine. A direct correlation was seen between current responsiveness and pyridine content (1.2–6.1 mmol), with detection limits of 1 mmol for adsorption and 1 μmol for direct addition to PAN/PIM-1 electrospun fibers. The findings highlight the potential of PAN/PIM-1 electrospun fibers for electrochemical and environmental sensing applications.