ZnO/ZnFe2O4 nanocomposite as a broad-spectrum photo-Fenton-like photocatalyst with near-infrared activity

Abstract

The majority of current photocatalysts are generally excited under ultraviolet (UV) and visible light, while near-infrared (NIR) light accounting for nearly half of solar light has not been fully used. Herein, a ZnO/ZnFe₂O₄ nanocomposite with the ability to degrade an organic dye in the presence of H₂O₂ under NIR irradiation was prepared by a co-precipitation method followed by calcination at 800 °C. As revealed by optical absorption analysis, the ZnO/ZnFe₂O₄ nanocomposite exhibits significant optical absorption in the UV, visible and NIR light regions. Benefitting from this unique photo-absorption property and the generation of reactive ˙OH mainly by the reaction of photogenerated electrons with H₂O₂, the ZnO/ZnFe₂O₄ nanocomposite performs well in photodegrading methyl orange under either UV, visible or NIR irradiation. Moreover, the UV, visible and NIR photocatalytic activities of the ZnO/ZnFe₂O₄ nanocomposite did not change significantly after three runs of recycling. This finding opens a new approach for fully utilizing solar light energy, especially the energy of NIR light.