Facile Fabrication of S-TiO2/β-SiC Nanocomposite Photocatalyst for Hydrogen Evolution under Visible Light Irradiation

A series of sulfate modified TiO2/β-SiC nanocomposite photocatalysts has been fabricated by sol–gel and wetness impregnation method by varying amount (5–20 wt %) of sulfate contents. The photocatalysts has been characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–visible diffuse-reflectance spectroscopy (UV–vis DRS), Brunauer–Emmett–Teller (BET) surface area, high resolution-transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), photoelectrochemical (PEC) measurement and photoluminescence (PL) florescent spectra study. The finding confirms that type (II) heterojunction exists between the crystal lattice of β-SiC and TiO2; alternatively, sulfate (S6+) is bidentately coordinated on the surface of TiO2. The existence of sulfate maintains the morphology as well as enhances the surface area, decreases the crystallite size, shifts the optical absorption toward the red end, enhances the generation of OH radical, acts as cocatalyst, and facilitat...