Adsorption and photocatalytic study of dyes for waste-water treatment using Mn modified DyCrO3 nanomaterials

In the present work, DyCr0.8Mn0.2O3 and DyCr0.5Mn0.5O(3) nanoparticles have been prepared via the sol-gel route and characterized by X-ray diffraction and UV-Visible Diffuse reflectance spectroscopy, SEM, EDX, and Photoluminescence spectroscopy. The influence of Mn substitution on the structural, optical, and photocatalytic properties of DyCrO(3 )has been studied. The XRD patterns confirm the orthorhombic phase of compounds with Pbnm space group. Furthermore, crystallite size of the nanoparticles is found to be 79.36 nm and 83.33 nm for DyCr0.8Mn0.2O3 and DyCr0.5Mn0.5O3, respectively. The optical bandgap energy of DyCr0.8Mn0.2O3 and DyCr0.5Mn0.5O3 compounds is 2.68 eV and 2.34 eV, respectively. The Photoluminescence spectrum exhibits blue, yellow and red emissions at 380 nm excitation wavelength. The dye degradation efficiency of DyCr0.8Mn0.2O3 and DyCr0.5Mn0.5O3 compounds was tested on MB and RhB dyes under solar light irradiation for 180 min. The highest degradation efficiencies for DyCr0.8Mn0.2O3 and DyCr0.5Mn0.5O3 compounds are 84% and 92% for RhB dye and 63% and 77% for MB dye in the presence of solar irradiation. The photodegradation kinetics obeys the first order linear kinetics and adsorption data follows pseudo second order model. Further, adsorption isotherms process follows the Langmuir and Freundlich model in the dark. [GRAPHICS]