Electrospun Zein Nanofiber as a Green and Recyclable Adsorbent for the Removal of Reactive Black 5 from the Aqueous Phase

Zein polymer is drawing intense research interest because of its nontoxicity, biodegradability, and unique structural properties. Zein-based electrospun nanofibers are prepared from an 80% ethanolic solution and are used as a nanoadsorbent material for the confiscation of reactive black 5 (RB5) dye from aqueous solutions. The electrospun nanofibers possessed an extraordinarily high capacity for RB5 uptake compared to their powder and film analogues. Zein nanofibers exhibited exceptionally efficient performance in removing RB5 after contact for only 20 min at room temperature and a normal working pH. The mechanism of dye–zein interaction was chiefly controlled via hydrophobic, electrostatic forces and hydrogen bond interactions. Experimental data followed a pseudo-second-order model, and the Langmuir adsorption isotherm was the most appropriate mechanism governing RB5 adsorption. The dye-loaded zein nanofibers were directly re-electrospun to achieve a recyclable and green adsorbent, preventing the consumption of toxic and expensive reagents for elution of RB5.