Role of EDTA capped cobalt oxide nanomaterial in photocatalytic degradation of dyes

Abstract

Dyes released from textile, paint, and various other industries in wastewater have posed long term environmental damage. Functional nanomaterials provide a hope and opportunities to treat these effluent wastes in a rapid and efficient way due to their large surface area to volume ratios. Synthesis of 2,2',2'',2'''-(ethane-1,2-diyldinitrilo)tetraacetic acid (EDTA) capped cobalt oxide nanomaterial, as a photocatalyst, has been investigated and used for the rapid and efficient removal of malachite green (MG) and crystal violet (CV) dyes. The morphological, structural, optical, chemical and thermal properties of the synthesized nanomaterial were analysed using different characterization tools such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, ultra violet?visible and Fourier transform infrared (FT-IR) spectroscopy and thermogravimetric analysis. The prepared EDTA capped cobalt oxide nanomaterials display better photocatalytic degradation, 56.3 % for MG and 37.9 % for CV in comparison to the pure cobalt oxide, 47.7 and 27.6 %, respectively, under visible light illumination. The kinetics of the degradation followed the pseudo-first order and it corresponds to Freundlich adsorption isotherm model. The incremental photodegradation of these two dyes was attributed by morphology of the nanomaterial which favour effective electron/ hole separation.