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.

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.