Facile access to highly flexible and mesoporous structured silica fibrous membranes for tetracyclines removal

Abstract

• Highly flexible and mesoporous silica nanofibrous membranes were fabricated. • The sample had large surface area (147.51 m 2 g −1 ) and pore volume (0.336 cm 3 g −1 ). • The maximum adsorption capacity of MPSNMs towards TCH was 53.29 mg g −1 . • TCH sorption capacity showed a linear relationship ( R 2 = 0.985) to mesopore volume. • Deduced binding mechanism was hydrogen bonding and electrostatic interaction. Ceramic-based porous fibers, benefitting from their high specific surface area, and superior thermal stability as well as chemical durability, are highly desirable for efficient tetracyclines removal from wastewater. However, the current ceramic porous fibers are commonly fragile with poor recyclability during application. Here, facile access to mesoporous structured silica nanofibrous membranes (MPSNMs) with superior flexibility, high specific surface area, and large mesopore volume is provided, that is, using phase separation-driven electrospinning technique and subsequent calcination processing. The obtained single mesoporous silica nanofiber could be circularly folded into half without any fracturing, which is comparable to the bending behavior of flexible polymer-based material. The resultant MPSNMs exhibited superior adsorption capability towards tetracycline hydrochloride (TCH) and outstanding recyclability, and the capacity could reach 53.29 mg g −1 , which is more superior to most of the currently reported inorganic-based adsorbents. Furthermore, based on the calculated results of reduced density gradient (RDG) analysis and non-covalent interaction (NCI) isosurfaces, the adsorption mechanism could be the synergetic effects of hydrogen-bonding interactions and electrostatic attraction between TCH and MPSNMs. This work not only enlightens the preparation of flexible mesoporous inorganic nanofibrous membranes but also provides a reference for designing and developing new kinds of adsorbents for various fields.