Synthesis and Structure of ZnO-Decorated Graphitic Carbon Nitride (g-C3N4) with Improved Photocatalytic Activity under Visible Light

The volume of dye production in the chemical industry is growing rapidly every year. Given the global importance of clean water resources, new wastewater treatment solutions are required. Utilizing photocatalysis by harvesting solar energy represents a facile and promising solution for removing dangerous pollutants. This study reports the possibility of increasing the photocatalytic activity of g-C3N4 by creating nanocomposites with ZnO. Exfoliated g-C3N4/ZnO nanocomposites were synthesized by heat treatment of urea and subsequent ultrasonic exfoliation of the colloidal solution by introducing zinc acetate. The uniformity of the distribution of ZnO nanoparticles is confirmed by the method of elemental mapping. The obtained X-ray diffractograms of the obtained nanocomposites show typical X-ray reflections for g-C3N4 and ZnO. It was found that the introduction of oxide into g-C3N4 leads to an increase in the specific surface area values due to the developed ZnO surface. The maximum value of the specific surface area was obtained for a sample containing 7.5% ZnO and was 75.2 m2/g. The g-C3N4/7.5% ZnO sample also demonstrated increased photocatalytic activity during the decomposition of methylene blue under the influence of visible light, which led to a twofold increase in the reaction rate compared to initial g-C3N4.