Effective H2O2-Free photo-Fenton processes over ZnSe nanosheets for photocatalytic degradation of dyes and antibiotics

• ZnSe nanosheet with H 2 O 2 -production activity was prepared via a solvothermal method. Generation and activation processes of H 2 O 2 is revealed in the presence of ZnSe and Fe 2+ . • H 2 O 2 -production rate decreases from 241 to 190 μmol• L − 1 • h − 1 after adding Fe 2+ in water. • Electrons can reduce Fe 3+ to Fe 2+ and achieves the circulation of iron ions in the system. • Photo-Fenton degradation of dyes or antibiotics follows the pseudo-first-order kinetic. Traditional Fenton process depends on adding additional H 2 O 2 , which is mainly produced by anthraquinone process involving large amounts of harmful organic solvents and H 2 , making a secondary pollution. In-situ photocatalytic generation of H 2 O 2 for Fenton-degradation is a promising way to remove pollutants. ZnSe nanosheets was obtained via a simple one-step solvothermal method using diethylenetriamine, hydrazine hydrate and water as reaction medium. ZnSe tends to produce H 2 O 2 under 300 W Xenon light irradiation, which then participates in Fenton reaction with the assistance of Fe 2+ to generate active hydroxyl radical for degradation of dyes and antibiotics, leading to the photocatalytic H 2 O 2 evolution rate decreases from 241 μmol· L − 1 · h − 1 in pure water to 190 μmol· L − 1 · h − 1 in Fe 2+ -contained solution. The photo-Fenton degradation rate of Methylene blue (MB), Tetracycline hydrochloride (TCH), Ciprofloxacin (CIP) is better than those of corresponding photocatalytic process and Fenton process alone, this is mainly attributed to the continuous generation and activation of H 2 O 2 in the presence of ZnSe and Fe 2+ based on a series of trapping experiments and related analysis. Besides, ZnSe also displays excellent stability and hydrophilicity in Fe 2+ -contained solution, which is benefit to the contact of catalyst and pollutants. Further investigation shows the kinetic of photo-Fenton degradation over ZnSe follows the pseudo-first-order kinetic.