A novel heterogeneous hybrid by incorporation of Nb2O5 microspheres and reduced graphene oxide for photocatalytic H2 evolution under visible light irradiation

Abstract

A novel heterogeneous hybrid composed of Nb₂O₅ microspheres and reduced graphene oxide has been first fabricated by a facile hydrothermal method. The as-prepared samples were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectroscopy (DRS) techniques. The results show that the Nb₂O₅ microspheres are well dispersed on the reduced graphene oxide (RGO) sheets and formation of Nb–O–C bond between the Nb₂O₅ microspheres and RGO results in superior interfacial contacts of the two components and promoted charges transportation and separation. The composite with optimal compositions shows an enhanced photocatalytic activity for hydrogen production from water reduction. Upon 10 h UV-vis light irradiation, ca. 8824 μmol g⁻¹ H₂ is produced over the photocatalyst consisting of 4 wt% RGO, which is ca. 3 times as high as that of the Nb₂O₅ microspheres.