Triple Axial Coelectrospun Multifunctional Double-Shell TiO2@ZnO Carbon Hollow Nanofibrous Mat Transformed to C-Attached TiO2 Brush-Like Nanotube Arrays: An Mo6+ Adsorbent Nonwoven Mat

A triple axial coelectrospinning procedure followed with a two-step heat treatment was successfully employed to fabricate continuous heterostructured multifunctional double-shell TiO 2 @ZnO graphite carbon nonwoven hollow nanofibrous mats. The as-synthesized TiO 2 @ZnO/C hollow heterojunctions were transformed to 3D high surface area rutile TiO 2 brush-like nanotube arrays attached onto carbon tubular mats under the alkaline hydrothermal and ion exchange processes combined with the annealing. The obtained TiO 2 nanotubes have a typical inner diameter of about 3.5 nm, wall thickness of about 4.0 nm, and length up to several hundred nanometers. Mathematical models as well as the experimental results exhibited a higher self-adsorption capacity of Mo 6+ pollutant over C-attached TiO 2 nanotubes can be attributed to the larger surface area, providing more active sites for a contact with the reactants and pollutants. Furthermore, the kinetic studies suggested that the pseudo-second-order model is suitable to describe the adsorption mechanism of Mo 6+ over the as-synthesized hollow nanostructures.