Inverse spinel NiFe2O4 deposited g-C3N4 nanosheet for enhanced visible light photocatalytic activity

The highly photocatalytic active magnetic NiFe2O4 deposited g-C3N4 hetero-structured nanocomposite was prepared by facile sol-gel followed calcination method. The Scanning Electron Microscope (SEM) result showed that the NiFe2O4 nanoparticles are deposited on g-C3N4 nanosheet. The High resolution Transmission Electron Microscope (HRTEM) analysis confirms the heterojunction between the NiFe2O4 and g-C3N4 nanoparticles. Compared with pure NiFe2O4 and pristine g-C3N4, the as prepared nanocomposite exhibits significantly higher photocatalytic degradation efficiency on methylene blue (MB) and rhodamine B (Rh B) dye in presence of visible light and direct sunlight irradiation. The magnetic nanocomposite NiFe2O4-g-C3N4 attains the maximum degradation efficiency of 99% under direct sunlight for both MB (20 mg/L) and Rh B (10 mg/L) dyes, which is quite higher than the efficiency obtained from the visible light irradiation. The enhanced photocatalytic activity of the nanocomposite attributed to the highly suppressed charge carriers recombination, better visible light absorption capability and the synergistic effect due to the heterojunction between NiFe2O4 and g-C3N4. From the radical trapping experiment it was observed that, the superoxide (O-2(-)) and hydroxyl (OH*) are the main active species for photocatalytic degradation process.