Hollow, Porous, and Flexible Co3O4-Doped Carbon Nanofibers for Efficient CO2 Capture

Hollow and porous fibrous materials have huge potential for gas filtration applications. However, synthesizing such carbonaceous materials is still a critical job owing to their inherent fragile nature. Herein, a facile strategy to fabricate porous, hollow, and flexible carbon nanofibers (CNF) for enhanced CO2 adsorption via biaxial electrospinning is reported. Polymethylmethacrylate (PMMA) is used in core as sacrificial precursor owing to its easy decomposition at relatively low temperature. Polyacrylonitrile (PAN) is opted as shell because of its tendency to produce high carbon yield. Co3O4 nanoparticles (NPs) are embedded in PAN shell to increase roughness and surface area through in situ synthesis from cobalt salt. Besides, uniform presence of Co3O4 NPs adds flexibility to the resultant hollow CNF (HCNF-Co) by serving as a plasticizer for single-fiber-crack connection and provides additional vacant oxygen sites to improve CO2 adsorption capacity. The optimized HCNF-Co nanofibers exhibit exceptional CO2 capture performance of 3.28 mmol g(-1) at 25 degrees C. Experimental results suggest that synthesized HCNF-Co also offers extremely high CO2 gas selectivity (S = 26) than N-2 gas. Meaningfully, porous, hollow, and flexible HCNF-Co nanofibers with exceptional structural stability overcome the limitations of annihilation and collapse of structures, making them a suitable candidate for the applications of CO2 capture.