Investigation of a new modified easy one-step hydrothermal method to synthesize Z-scheme gC3N4-TiO2 compositesfor enhanced photocatalytic mineralization of sodium diclofenac under simulated solar light irradiation

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Vol. 456
• Main Authors: Abega, Aimé Victoire, Marchal, Clément, Dziurla, Marie-Antoinette, Robert, Didier
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2024
• Subjects: Diclofenac; gC3N4/TiO2; Photocatalysis; Z-scheme; Photocatalysis; Z-scheme; gC3N4/TiO2; Diclofenac
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2024.115850

•Solvent expulsion as a reverse spray during gCNT synthesis in the closed crucible promotes porosity development.•The creation of moderate surface defects has modified the migration path of photogenerated species and improved the absorption of electromagnetic radiation from visible light.•Both Ostwald ripening and particle diffusion/coalescence theories can explain nanoparticle growth with increasing temperature. Efficient TiO2/g-C3N4 (gCNT) heterojunction z-scheme photocatalysts with well-defined multiscale and dispersed TiO2 were synthesized using a modified hydrothermal process. This photocatalyst efficiently mineralize sodium diclofenac (SDFC) from water under simulated solar light irradiation. This improvement photocatalytic behaviour compared to raw materials is the result of synergetic effects due to high quality assembly, moderate defects, good surface area, interface between the two components and the good dispersion of TiO2 nanoparticles on gCN surface. At the optimal calcining temperature (500 °C), degradation and mineralization percentage achieved 99.99 % and 75 % respectively. This result excellent photo-mineralization of SDFC on this optimized nanoscale assembly was attributed to the formation of Z-scheme gCNT heterojunctions due strong interaction between gCN and TiO2 nanoparticles. A series of radical trapping experiments showed that superoxide ions and photo-generated holes play major roles in the photo-mineralization process while hydroxyl radicals are also involved with a minor role.