Enhanced visible light-driven photocatalytic activity of green synthesized cobalt ferrite nanoparticles

Abstract

Cobalt ferrite nanoparticles were synthesized through green synthesis using Erythrina variegata leaf extract. The presence of phytonutrients in the Erythrina variegata leaf extract was confirmed by phytonutrient screening analysis. The thermal, structural, optical, functional, chemical, morphological, and compositional properties of prepared nanoparticles were analysed. The crystal violet (CV) and congo red (CR) dyes eliminated from water using CoFe2O4 NPs as an adsorbent, has been reported. The thermal stability of as-prepared samples was studied by TG-DTA and powder XRD analysis exhibits a cubic inverse spinel structure. By using UV–Vis spectroscopy, the lower band gap energy of CoFe2O4 NPs was found to be around 1.86 eV. The relevant FTIR and Raman spectra indicated Fe–O (tetrahedral site) and Co–O (Octahedral site) band, which attributed to the stretching vibration modes. The cubic-shaped and irregular agglomerated particles was examined from SEM images. The existence of all required elements in prepared CoFe2O4 NPs were confirmed by EDX and XPS analysis. Leaching experiment using the seed germination method for CoFe2O4 catalyst was evaluated. Moreover, the effective photocatalytic performance of crystal violet (CV) and congo red (CR) dye adsorption using CoFe2O4 catalyst within 120 min on the effect of pH, dye dosage, exposure time, and kinetic studies under visible light were investigated. The maximum dye removal efficiency of 85.18 % and 79.58 % was observed using 25 mg/L at pH 9 for CV and CR dyes, respectively. Trapping experiments revealed that O2•− is the major active species in the dye degradation. Recycling experiments revealed good stability after three cycles for CoFe2O4 catalyst. As a result, the prepared CoFe2O4 NPs can be utilized as an effective adsorbent for wastewater treatment.