Fabrication of high-activity hybrid NiTiO3/g-C3N4 heterostructured photocatalysts for water splitting to enhanced hydrogen production

Abstract

Novel NiTiO3/g-C3N4 hybrid photocatalysts were designed and fabricated for photocatalytic water splitting by harvesting solar energy. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectra (XPS), ultraviolet-visible diffuse reflection spectroscopy (DRS), photoluminescence spectroscopy (PL) and electrochemical impedance spectroscopy (EIS). The hydrogen evolution rate under visible light irradiation was measured in triethanolamine aqueous solution and NiTiO3/g-C3N4 hybrids demonstrate a much higher photocatalytic activity than pure g-C3N4 particles. Furthermore, it was observed that the rod-like NiTiO3 coupled with g-C3N4 showed better performance than the bulk flocculent NiTiO3 coupled with g-C3N4. When the content of rod-like NiTiO3 in NiTiO3/g-C3N4 hybrid catalysts was 3wt%, the catalysts exhibited optimal activity, the rate of hydrogen generation was about 3 folds that of pure g-C3N4. The enhanced photocatalytic performance could be attributed to the strong light absorption in the visible region and the low recombination rate of photogenerated electrons and holes.