Electrospinning construction of Bi2WO6/RGO composite nanofibers with significantly enhanced photocatalytic water splitting activity

Abstract

Bi₂WO₆/reduced graphene oxide (RGO) composite nanofibers were successfully fabricated by calcining electrospun PVP/RGO/[(NH₄)₁₀W₁₂O₄₁ + Bi(NO₃)₃] composite nanofibers. The products were investigated in detail by X-ray diffraction technique (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) method, UV-Vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy (XPS). Furthermore, photoluminescence spectra (PL) and electrochemical impedance spectroscopy (EIS) of the samples were determined to explain the mechanism for the significant enhancement of the photocatalytic performance of the Bi₂WO₆/RGO composite nanofibers. Bi₂WO₆/RGO composite nanofibers are pure orthorhombic phase with a space group of B2ab, and the diameter is 132 ± 11 nm. Bi₂WO₆/RGO composite nanofibers are composed of nanoparticles with the diameter ranging from 30 nm to 50 nm. The Bi₂WO₆/6%RGO composite nanofibers used for photocatalytic water splitting exhibit the highest H₂ production, which is improved by 5.8 times compared to pure Bi₂WO₆ nanofibers. This could be ascribed to two points: the one-dimensional Bi₂WO₆/RGO composite nanofibers constructed by electrospinning technique have a better capability of electron transportation and intimate interfacial contact area between Bi₂WO₆ and RGO; the addition of RGO gives rise to excellent conductivity which could transfer the photogenerated electrons quickly and inhibit the recombination of electrons and holes. The study provides a new method to prepare photocatalytic material for converting water and solar energy to clean energy.