Composite Photocatalysts g-C₃N₄/TiO₂ for Hydrogen Production and Dye Decomposition

The photocatalytic activity of the g-C₃N₄/TiO₂ composite samples in the processes of dye (methylene blue) decomposition and hydrogen evolution from an aqueous ethanol solution under the action of visible radiation (400 nm) has been studied. A new original method for the synthesis of the g-C₃N₄/TiO₂ composite by depositing g-C₃N₄/TiO₂ to TiO₂ nanoparticles during sol-gel synthesis is proposed. The synthesized photocatalysts were characterized by X-ray diffraction, low-temperature gas adsorption, X-ray photoelectron spectroscopy, high-resolution transmission microscopy, and diffuse reflectance spectroscopy in the UV and visible regions. The maximum activity in the hydrogen evolution reaction was 1.3 mmol \({\text{g}}_{{{\text{cat}}}}^{{ - 1}}\) h^–1, which exceeds the rate of hydrogen evolution on the unmodified g-C₃N₄ and TiO₂ samples.