Facile stir-dried preparation of g-C3N4/TiO2 homogeneous composites with enhanced photocatalytic activity

Abstract

g-C₃N₄/TiO₂ composites with homogeneous well-combined structures were prepared by a simple stir-dried method, using dicyandiamide (DICY) and tetrabutyl orthotitanate (TBOT) as the precursors, followed by high-temperature calcination. Various characterization techniques including XRD, FTIR, nitrogen adsorption–desorption, SEM and XPS confirm the formation of an interconnected structure between g-C₃N₄ and TiO₂ in the composites. g-C₃N₄/TiO₂ composites exhibit much higher photocatalytic activity than that of pure g-C₃N₄ and TiO₂ in the degradation of methylene blue under visible light. In particular, the CT-5 composite prepared with DICY/TBOT at a mass ratio of 5 : 1, exhibited a photodegradation activity that is about 3.8 times that of TiO₂ and 2.9 times that of pure g-C₃N₄. The homogeneous g-C₃N₄/TiO₂ composite CT-5 can be repetitively used without significant loss of activity. The strong synergistic effect between g-C₃N₄ and TiO₂ achieved by this preparation method greatly improves the separation efficiency of photo-generated electrons and holes, thus offering enhanced photocatalytic performances.