Recently, photocatalysts have been attracting much attention due to application in the different humanity problems such as air and water purification, generation of green fuels via water splitting and CO2 reduction. One of the most popular photocatalysts actively studied in the present is graphitic carbon nitride (g-C3N4). g-C3N4 demonstrates significant photocatalytic performance even in the visible range, but its efficiency is limited by the recombination of photogenerated electron hole pairs. Formation of composites such as g-C3N4/WO3 improves photocatalytic properties compared to the individual catalyst due to separation charge carriers on the semiconductors contact.
The aim of this research was determination of optimal conditions in the hydrothermal synthesis resulting in both WO3 nanoparticles precipitation on the g-C3N4 surface and saving initial g-C3N4 structure. Thereby, we synthesized g-C3N4/WO3 composites via hydrothermal treatment of g-C3N4 in the acidic tungstates solutions and studied synthesis parameters effect on the obtained composites’ structure and photocatalytic activities. Initial g-C3N4 was obtained using classical melamine thermolysis approach. On the other hand, its structure and composition changes under hydrothermal condition were determined by FTIR-spectroscopy and CHNO-analysis. Hydrothermal syntheses of composites g-C3N4/WO3 were carried out at different treatment times and pH values. Powder XRD analysis with SEM data proved WO3 formation on the g-C3N4 surface from sodium tungstate solution. The studying of the photocatalytic performance of the WO3/g-C3N4 composites was evaluated in the reaction of hydrogen peroxide generation from oxygen under UV irradiation. The WO3/g-C3N4 composites demonstrated three times better photocatalytic activity than the individual semiconductor photocatalyst obtained in the same conditions.
