Structural, photocatalytic, and anticancer activity Ni-substituted Cu nanochromites synthesized by citrate gel auto-combustion method

Nickel-doped copper nanostructured chromites of Cu1-xNixCr2O4 (x = 0.0 to 1.0 with 0.2 variation) were synthesized by the citrate gel auto-combustion, and these are described using various experimental methodologies like X-ray diffraction analysis (XRD), field emission scanning electron microscope (FESEM), energy-dispersive X-ray analysis (EDS), UV-visible, Fourier-transform infrared (FTIR), and photoluminescence (PL). X-ray diffraction analysis was used to confirm the phase and crystalline size of the synthesized samples. Using SEM, surface morphology and shape were determined. EDS analysis confirmed the presence of elements such as Cu, Ni, Cr, and O in nickel-doped copper chromite. Two major absorption band are observed in FTIR spectra, which confirms the stretching frequencies of the tetrahedral and octahedral sites. Materials optical band gap energy and cut-off wavelength of the samples were calculated from UV-Vis spectra, and band gap energy was decreased from 2.79 to 2.10 eV with substitution of Ni. The photoluminescent (PL) studies revealed the broad near band-edge emission in visible wavelength range (similar to 570 nm) for all the samples. Photocatalytic studies of organic azo dyes like methylene blue and acid red with synthesized samples of Cu1-xNixCr2O4 (where x = 0.0, 0.4, and 1.0) were conducted using UV light. The results show that the highest degradation is obtained for nickel-doped cupper (Cu0.6Ni0.4Cr2O4) nanochromites. The Anticancer activity of spinel chromite was studied on the HeLa cell line, and IC50 values were calculated.