Synthesis, structural, photocatalytic and anti-cancer activity of Zn doped Ni nano chromites by citrate gel auto combustion method

Nano structured zinc doped nickel chromites Ni1-xZnxCr2O4 (where 0 <= x <= 1 by step 0.2) were fabricated by the citrate gel auto combustion route and were characterized with several techniques like XRD, SEM, EDS, Transmission Electron Microscope (TEM), FT-IR, UV-Vis and Photoluminescence. A formation of single-phase cubic structure and the crystalline state of fabricated samples in size range of 9-to-20 nm were established by the X-ray diffraction studies. The SEM images have revealed the shape of Ni substituted Zn nano chmmite. The existence of Ni, Zn, Cr and O in the series of samples were also confirmed by the elemental analysis (EDS) study. FTIR spectra revealed the formation of metal oxide bands and spinel chromite structures which have tetrahedral and octahedral stretching frequency bands. Using the UV-Vis spectrometer, the optical properties of Ni-Zn chmmite has been studied and also have that the band gap energy of Ni chromite (3.54 eV) is smaller than that of Zn chromite (3.85 eV). The optical band gap energies were found to be 2.10-3.08 eV for the direct band gap calculated from Tauc plots. The present study mainly focused on the photo-degradation of methylene blue and acid red on the NiZn chromite's under UV light. The chromites have shown good and clear degradation at certain time intervals with the reference. The biological activity of the synthesized Ni-Zn chromites were performed for their anticancer activity on Hela cell lines and all the molecules exhibited with different IC50 values ranging from 21.83 to 74.15.