Adsorption of Carbon Dioxide with Ni-MOF-74 and MWCNT Incorporated Poly Acrylonitrile Nanofibers.

Among the new adsorbent forms, nanofiber structures have attracted extra attention because of features such as high surface area, controllable properties, and fast kinetics. The objective of this study is to produce the polyacrylonitrile (PAN) electrospun nanofibers loaded with Ni-MOF-74/MWCNT to obtain maximum CO adsorption. The prepared PAN/MWCNT/MOF nanofiber based on the Box-Behnken design (BBD) model suggests the CO adsorption of about 1.68 mmol/g (at 25 °C and 7 bar) includes 14.61 /%, 1.43 /%, and 11.9 /% for PAN, MWCNT, and MOF, respectively. The results showed the effective CO adsorption of about 1.65 ± 0.03 mmol/g (BET = 65 m/g, pore volume = 0.08 cm/g), which proves the logical outcomes of the chosen model. The prepared PAN/MWCNT/MOF nanofiber was characterized using different analyzes such as SEM, TEM, TG, XRD, FTIR, and N adsorption-desorption isotherms. More MOF mass loading on the nanofiber surface via secondary growth method resulted in 2.83 mmol/g (BET = 353 m/g, pore volume = 0.22 cm/g, 43% MOF mass loading) and 4.35 mmol/g (BET = 493 m/g, pore volume = 0.27 cm/g, 65% MOF mass loading) CO adsorption at 7 bar for the first and second growth cycles, respectively. This indicates that secondary growth is more effective in the MOF loading amount and, consequently, adsorption capacity compared to the MOF loading during electrospinning.