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

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.