Electrospun carbon nanofibers with multi-aperture/opening porous hierarchical structure for efficient CO₂ adsorption

Carbonaceous materials are believed to be excellent source for developing essential vessels for carbon dioxide (CO₂) adsorption. However, most of the carbonaceous materials used for CO₂ capture have particle form, which is hard to recycle and also may cause choking of the gas pipes. Additionally, they also either require chemical activation or attachment of any functional groups for proficient CO₂ capture. Thus, facile fabrication of multi-aperture porous carbon nanofiber (CNF) based CO₂ sorbent via combination of three simple steps of electrospinning, washing, and carbonization, may be an effective approach for developing efficient sorbents for CO₂ capture.

PAN/PVP composite solution was electrospun, PVP was used as pore forming template and PAN was opted as nitrogen rich precursor for carbon during electrospinning process. Selective removal of PVP from the electrospun PAN/PVP fiber matrix prior to carbonization generated highly rough and extremely porous PAN nanofibers, which were then carbonized to develop multi-aperture/opening porous carbon nanofibers (PCNF) with ultra-small pores with average pore diameter of ~0.71 nm.

Synthesized PCNF exhibited high CO₂ gas selectivity (S = 20) and offered superior CO₂ adsorption performance of 3.11 mmol/g. Moreover, no apparent change in mass for up to 50 cycles of CO₂ adsorption/desorption unveil the long-term stability of synthesized PCNF, making them a potential candidate for CO₂ adsorption application.