Washable and flexible gas sensor based on UiO-66-NH2 nanofibers membrane for highly detecting SO2

UiO-66-NH2 was loaded onto the surface of PAN nanofibers by simulating flower clusters on branches. Not only can the dispersibility of MOFs particles be improved, but the material maintains the pore structure of the nanofiber membrane. Gas molecules can quickly diffuse into the interior of the dielectric layer, which improves the performance of the sensor. [Display omitted] •UiO-66-NH2 was loaded on the surface of PAN nanofibers by in-situ growth.•The in-situ growth method is beneficial to improve the sensitivity of the sensor.•The sensor has linear response for SO2 in the concentration range of 1–125 ppm.•The sensor maintains stable sensing performance for SO2 gas after 30-days.•UiO-66-NH2 mainly through the NH2 and metal active sites to adsorb SO2 molecules. Zr-based MOFs has presented great potential and excellent performance in gas detection. However, MOFs in powder form severely limits its application for fabricating into devices with air-permeability and flexibility. Herein, we describe an environmental benignity strategy of developing a flexible sensing layer involving UiO-66-NH2 incorporated into nanofibers through electrospinning and aqueous synthesis. Benefiting from high porosity, excellent flexibility and fully dispersed adsorption active sites, the achieved capacitive sensor constructed by UiO-66-NH2 nanofiber membrane and carbon nanotubes shows outstanding sensitivity and long-term stability to SO2 gas in the range of 125 ppm to 1 ppm. There are almost no obvious changes of the response value in the tested period of one month. Also, the fabricated sensor can detect SO2 as low as 1 ppm with a high linear response (R2 = 0.996). Moreover, the sensing performance can still be remained as high as 73.33% after washing for 24 h. Significantly, UiO-66-NH2 nanofiber membrane sensor provides superior selectivity towards SO2 compared with other environmental hazardous gases.