Tuning porous silica nanofibers by colloid electrospinning for dye adsorption

Porous silica nanofibers were prepared by electrospinning alkoxide precursors and sacrificial polystyrene nanoparticles (PSNs). The multi-compartmented fibers were electrospun from a mixed solution of colloidal particles and poly (vinyl pyrrolidone), added with tetraethyl orthosilicate and acetic acid. The colloidal particles were embedded into the resultant fibers with a close-packing structure. After air calcination, the removal of polymeric particles created porous silica nanofibers. The pore size of the silica nanofibers ranges from micropores (∼3 nm) to mesopores (∼50 nm), and can be precisely controlled by changing the weight ratio of the PSNs. Such hierarchical porous nanofibers have been demonstrated as a promising candidate for dye adsorption. The dye absorption ability was enhanced as more mesopores were created, although the specific surface area simultaneously decreased with the decrease of micropores.