Magnetic binary metal oxide intercalated g-C3N4: Energy band tuned p-n heterojunction towards Z-scheme photo-Fenton phenol reduction and mixed dye degradation

The magnetic ZnFe2O4 (ZFO) intercalated g-C3N4 (g-CN) energy band tuned p-n heterojunction has been successively synthesized by facile sol-gel followed calcination method. The various analytical characterization techniques were carried out on the prepared photocatalysts to probe the structural, morphological, chemical compositional and magnetic properties. Surface defect of the composite catalyst was confirmed by the presence of shoulder peaks in the UV-DRS absorption spectrum. The formation of heterojunction between the g-CN and ZFO nanoparticles was confirmed by HRTEM micrograph. The surface defect presented type-II heterojunction produce the energy band bend in the catalyst and results the Z- scheme heterojunction which leads to enhance the visible light catalytic activity. The visible light driven photo-Fenton 4- nitrophenol (4-NP) reduction and mixed dye solution (MDS) degradation was performed with the aid of chemical oxidant under natural sunlight. The nanocomposite 0.5 ZF/g-CN photocatalyst shows the better redox process compared with the other nano-photocatalysts. The enhanced degradation efficiency attributed to the synergistic effect of interfacial contact between the nanoparticles. The Z-scheme photocatalytic degradation process and active radicals for Photo-Fenton process was investigated through elemental trapping experiment.