Enhanced Photocatalytic Performance of Hierarchical ZnFe2O4/g-C3N4 Heterojunction Composite Microspheres

Semiconductor photocatalysts with suitable band gap for fair response to visible light and efficient separation of electron-hole pairs, are the key to practical application of photocatalytic technology. Magnetically separable hierarchical ZnFe2O4/g-C3N4 composite photocatalysts were prepared by a facile solvothermal method combined with a subsequent annealing process. The composite microspheres were composed of ZnFe2O4 nanoparticles, whose diameter was restricted due to the confined space effect from g-C3N4 nanosheets. ZnFe2O4/g-C3N4 heterojunction structures led to the improvement of the efficiency for photodegrading methylene blue and rhodamine B under visible light, where the kinetic constant over ZnFe2O4/CN-150 photocatalyst was more than ten times larger than that over pure ZnFe2O4. The photogenerated electrons from g-C3N4 surfaces could easily migrate to ZnFe2O4, leading to efficient separation of electron-hole pairs. Also, the composite photocatalyst possessed a chemical stability against photocorrosion and a magnetic property, which made it magnetically separable and reusable conveniently. [GRAPHICS] .