A facile in situ approach to fabricate N,S-TiO2/g-C3N4 nanocomposite with excellent activity for visible light induced water splitting for hydrogen evolution

Abstract

A series of novel N,S-TiO₂/g-C₃N₄ nanocomposite (abbreviated as TuT) photocatalysts has been synthesized via a facile, cost effective, in situ thermal induced polymerization method. The as-synthesized nanocomposites were thoroughly characterized through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-vis diffuse reflectance spectroscopy (UV-Vis DRS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and photo luminescence spectroscopy (PL). Using UV-Vis DRS, a gradual enhancement in visible light absorption towards the red end was observed for the xTuT photocatalyst in comparison to bare g-C₃N₄ (Tu). The result demonstrates that thermal reaction of a higher wt% of thiourea with respect to Ti precursor causes coupling of the N,S-TiO₂ and g-C₃N₄ nanocomposite, however at a lower wt% only N,S-TiO₂ forms. The photocatalytic activity has been evaluated through H₂ evolution. The synergistic combination of small crystallite size, the crystalline anatase phase, enhanced visible light absorption ability, enhanced specific surface area and the effective charge separation properties of the 10TuT photocatalyst makes the system pivotal for photocatalytic H₂ evolution under visible light irradiation.