ZnO/ZnFe2O4 nanocomposite as a broad-spectrum photo-Fenton-like photocatalyst with near-infrared activity
The majority of current photocatalysts are generally excited under ultraviolet (UV) and visible lights, while near-infrared (NIR) light accounting for nearly half of solar light has not been fully used. Herein, ZnO/ZnFe2O4 nanocomposite with the ability to degrade an organic dye in the pesence of H2O2 under NIR irradiation was prepared by a co-precipitation method followed by calcination at 800 °C. As revealed by an optical absorption analysis, the ZnO/ZnFe2O4 nanocomposite exhibits significant optical absorptions in 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 ZnO/ZnFe2O4 nanocomposite are not changed significantly after three runs of recycling. This finding opens a new approach for fully utilizing solar light energy especially the energy of NIR light.