Enhanced Visible-Light Photocatalytic Performance of Electrospun rGO/TiO₂ Composite Nanofibers

Abstract

Reduced graphene oxide (rGO) / Titanium dioxide (TiO2) composite nanofibers as photocatalytic materials were successfully elaborated by using electrospinning. The as-spun nanofibers with controlled ratio of rGO were annealed at 500°C under Nitrogen in a tubular furnace.Structural, morphological and optical characterizations demonstrate the success of rGO incorporation in the TiO2 nanofibers. The performances of these nanocomposites for photocatalytic application have been evaluated. The presence of rGO sheets decreases the band gap energy of TiO2 NFs from 3.2 eV to 2.9 eV. Hence, in the photodegradation of methyl orange (MO), a significant enhancement in the reaction rate was observed with rGO/TiO2 (2wt. %) composite NFs compared to commercial TiO2-P25. In addition, the kinetic of MO degradation by rGO/TiO2 (2wt. %) composite NFs is 6 times higher than that by commercial TiO2. Thus, the photocatalytic activity of the composites rGO/TiO2 significantly increases the visible light photo-response and improves the separation of photo-induced electron-hole pairs of TiO2.

Recent Progress on Titanium Dioxide Nanomaterials for Photocatalytic Applications

“…[67] In the electrospinning process, the morphology and uniformity of the nanofibers are determined by an umber of parameters that can be separated into two main themes:1 )polymer/solution properties such as molecular weight, viscosity,c onductivity,s urfacet ension; 2) set-up parameters such as the electric field, the flow rate of the solution,a nd tip-to-collectord istance. [71] To increase the active surfacea rea of the TiO 2 nanofibers, the authors prepare different TiO 2 -based composite and co-doped nanofibers, such as graphene-TiO 2 , [72] BN-TiO 2 , [73] ZnO/TiO 2 , [74] CuO/TiO 2 , [75] and Ag/ TiO 2 , [76] by electrospinning. [68,69] In general, the elaboration of TiO 2 nanofibersb yu sing electrospinning involves the following three steps:1 )preparation of the electrospun solution with the titania precursor and ap olymer template;2 )electrospinning of the solution to obtain the composite nanofibers;3 )cal-cination of the as-prepared nanofibers to remove the polymer and to obtain the crystalline phase of the TiO 2 nanofibers.…”

From Synthesis to Applications: Copper Calcium Titanate (CCTO) and its Magnetic and Photocatalytic Properties

“…TiO 2 is acclaimed as a UV‐light photocatalytic. To enhance TiO 2 performance in visible light, many approaches investigate the doping of TiO 2 with metal transitions . While doping, a disordered structure could appear in TiO 2 , limiting the efficiency of this approach.…”

“…The crystalline phases of barium titanate varied at different temperatures. It is paraelectric at high temperature with a cubic phase, tetragonal and polarized below its Curie temperature (T c =120 °C), orthorhombic and polarized below 5 °C, and rhombohedral and polarized below −90 °C.…”

Incorporation of reduced graphene oxide into faceted flower-like {001} TiO 2 for enhanced photocatalytic activity

“…Owing to its unique properties, several researchers have attempted to introduce graphene to modify TiO 2 towards the improvement of its photocatalytic activity [22,23]. …”