Porous, flexible, and core-shell structured carbon nanofibers hybridized by tin oxide nanoparticles for efficient carbon dioxide capture

Carbon based nanofibrous materials are considered to be promising sorbents for the CO2 capture and storage. However, the precise control of porous structure with flexibility still remains a challenging task. In this research, we report a simple strategy to develop tin oxide (SnO2) embedded, flexible and highly porous core-shell structured carbon nanofibers (CNFs) derived from polyacrylonitrile (PAN)/polyvinylidene fluoride (PVDF) core-shell nanofibers.PAN/PVDF core-shell solutions were electrospun using co-axial electrospinning process. The as spun PAN core, and PVDF shell, with an appropriate amount of SnO2, fibers were stabilized followed by carbonization to develop SnO2 embedded highly porous and flexible core-shell structured CNFs.The optimized CNFs membrane shows a prominent CO2 capture capacity of 2.6 mmol g-1 at room temperature, excellent CO2 selectivity than N2, and a remarkable cyclic stability. After 20 adsorption-desorption cycles, the CO2 capture capacity retains >95% of the preliminary value showing the long-term stability and practical worth of the final product. The loading of SnO2 nanoparticles in the carbon matrix not only enhanced the thermal stability of the precursor nanofibers, their surface characteristics, and porous structure to capture CO2 molecules, but also improves the flexibility of the CNFs by serving as a plasticizer for single-fiber-crack connection. Meaningfully, the flexible SnO2 embedded core-shell CNFs with excellent structural stability can prevail the limitations of annihilation and collapse of structures for conventional adsorbents, which makes them strongly useful and applicable. This research introduces a new route to produce highly porous and flexible materials as solid adsorbents for CO2 capture.