Urea and green tea like precursors for the preparation of g-C3N4 based carbon nanomaterials (CNMs) composites as photocatalysts for photodegradation of pollutants under UV light irradiation

Abstract

To overcome the drawbacks of pure g-C3N4 in photocatalysis, namely insufficient light absorption and fast recombination of its photogenerated charges, g-C3N4-based nanocomposites were investigated. In detail, this study focuses on a novel route by which carbon nanomaterials (CNMs) might be inserted into the structure of g-C3N4 to form hybrid materials that possess great surface area with high photocatalytic and adsorption properties. The g-C3N4/CNMs composites with high photo-activity were obtained via a one-pot synthesis using urea and green tea leaves as cheap and renewable materials. After exfoliation, porous nanosheets with a surface area of about 128 m2 g−1, providing more active sites for both adsorption and efficient photocatalytic degradation of methylene blue, were obtained. The green tea leaves seem to act as a templating agent that control the morphology, growth, and final structure of the composite. From the first-order kinetic model, the reaction rate constant for the nanosheets g-C3N4/CNMs was determined to be kapp =4.7 min−1, which was approximately more than twice that of pure nanosheets g-C3N4 (kapp = 2.0 min−1). Besides, the g-C3N4/CNMs nanocomposite shows an accurate reusability and stability as compared to g-C3N4.