Synthesis and characterization of low-cost g-C3N4/TiO2 composite with enhanced photocatalytic performance under visible-light irradiation

Abstract

The influence of g-C3N4 in TiO2 photocatalyst on photodegradation of organic pollutant in aqueous solution has been investigated in the present study. The g-C3N4 was synthesized from low cost urea and used as precursor to synthesize g-C3N4/TiO2 composite by wet impregnation method. The synthesized g-C3N4 and g-C3N4/TiO2 composite photocatalysts were thoroughly characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and UV–vis diffuse reflectance spectroscopy. The photocatalytic performance of pure g-C3N4, pure TiO2 and g-C3N4/TiO2 composite photocatalysts were evaluated for the photodegradation of acid orange 7 (AO7) under visible light irradiation. The photocatalytic experiments demonstrated that the g-C3N4/TiO2 composite photocatalyst showed much better photocatalytic degradability of AO7 than the pure TiO2 and g-C3N4. This may be due to the increased absorption of light in the visible region and also by a lower recombination of charge-carriers. Further, the photoelectrochemical measurements of g-C3N4/TiO2 revealed the faster migration of photo-induced charge-carriers. This study demonstrates that g-C3N4/TiO2 composite can be a good candidate for environmental remediation of polluted waters.