Type-II heterojunction-based magnetic ZnFe2O4@CuFe2O4@SiO2 photocatalyst for photodegradation of toxic dyes from wastewater

Fabrication of a Type-II heterojunction has been deliberated as a particular strategy to enhance the photocatalytic efficiency of semiconductor photocatalysts to eliminate organic contaminants. The present study represents a unique recyclable Type-II-based ZnFe2O4@CuFe2O4@SiO2 heterojunction synthesized via facile coprecipitation technique. The as-prepared samples were characterized via XRD, FTIR, SEM, XRD, TEM, UV–Vis DRS, VSM, XPS, and PL studies. The comparative photocatalytic performance of ZnFe2O4@CuFe2O4@SiO2 heterojunction and pristine CuFe2O4, ZnFe2O4 was examined for removal of Methylene Blue (MB) dye under visible light. The core–shell construction imparts reusability via magnetic retrieval, and SiO2 acted as an effective host for the ZnFe2O4@CuFe2O4 photocatalyst. The degradation efficacy of MB over ZnFe2O4@CuFe2O4@SiO2 heterojunction reached 98.6% after 70 min under visible light radiation. Photocatalytic results also demonstrated that hybrid heterojunction owns about 9.3 times greater photocatalytic activity than bare CuFe2O4 and 5.47 times higher than bare ZnFe2O4 nanocomposite. The mechanism evaluation indicated that accelerated photocatalytic performance was allied with SiO2 mediated hybrid, directing to a remarkable separation of electron–hole pairs and high redox proficiency in photocatalysis. Moreover, the ZnFe2O4@CuFe2O4@SiO2 junction displayed broad pH compliance, exceptional magnetic recyclability, and good photo-stability. In conclusion, a probable degradation pathway of MB over ZnFe2O4@CuFe2O4@SiO2 heterojunction was anticipated through regulated degradation intermediates. The present portrays a comprehension of the construction of favorable and novel ZnFe2O4@CuFe2O4@SiO2 heterojunction for various environmental applications.