Efficiency of CuCr₂O₄/Titanium dioxide nanoparticles composite for organic dye removal in aqueous solutions

Semiconductor metal oxide with TiO₂ nanoparticles removes hazardous compounds from environmental samples. TiO₂ nanoparticles have shown potential as an efficient photocatalyst by being employed as a nano-catalyst for the breakdown of organic contaminants in wastewater samples. To separate substances from contaminated samples, combined UV and visible light irradiation has been used. Sol-gel synthesis was used to produce a copper chromite-titanium nanocomposite, which was then evaluated using analytical methods, such as XRD, BET, DRS-UV, and FT-IR. Using visible light, the photocatalytic activity of a nanocomposite made of CuCr₂O₄ and TiO₂ was investigated for its role in the breakdown of malachite green. The effects of several parameters, including pH change, anions presence, contact time, catalyst amount, concentration variation, and the kinetics of photocatalytic degradation were investigated. The magnitude of transition energy calculated using UV-DRS spectra was found to be 3.1 eV for CuCr₂O₄^-TiO₂ nanocomposite. Maximum degradation was observed at pH 7.0. The surface area and pore volume of the co-doped samples of Cr₂O₄ - TiO₂ obtained from BET were found to be 6.1213 m²/g and 0.045063 cm³/g respectively. The average particle size of the catalyst of the nano-catalysts calculated from XRD was found to be 8 nm for TiO₂ and 66 nm for TiO₂-CuCrO₄. The peaks obtained in FTIR between the range of 900-500 cm^-1 were due to the presence of an aromatic compound. The binding mechanism of a dye molecule to the surface of CuCr₂O₄-TiO₂ nanocomposite was analysed using quantum chemical calculations with the self-consistent reaction field technique employing integral equation formalism for the polarized continuum method and the UFF atomic radii set.