Superior organic dye removal by CoCr2O4 nanoparticles: Adsorption kinetics and isotherm

Abstract

In the present work, we report on the dye removal efficiency of Cobalt chromite, CoCr 2 O 4 nanoparticles synthesized via the solvothermal method. The obtained CoCr 2 O 4 nanoparticles demonstrated that the dye removal efficiency of CoCr 2 O 4 nanoparticles could be enhanced by a reduction of size or improved water dispersibility. The pseudo-second-order kinetic model best describes the adsorption of Congo red (CR) dye on CoCr 2 O 4 nanoparticles. The Langmuir adsorption isotherm model fitted best for the adsorption process and the adsorption capacity for CCO@450 and CCO@550 nanoparticles were found to be 59.4 and 43.8 mg g −1 , respectively. Dye adsorption studies on a mixture of CR, MB, and RhB dyes solution revealed that the MB removal efficiency of CoCr 2 O 4 nanoparticles could improve to 81% compared to 55% in solo MB solution. With the ease of use, high stability, diverse working environment, and superior adsorption capacity, CoCr 2 O 4 nanoparticles have the potential to be used as an organic dye removal adsorbent for wastewater treatment. • CoCr 2 O 4 nanoparticles (8 and 17 nm) were synthesized using solvothermal reaction. • CoCr 2 O 4 nanoparticles exhibited rapid, and high dye removal efficiency of 87% within 30 min of exposure towards CR aqueous solution. • Langmuir adsorption isotherm model showed an adsorption capacity of 59.4 and 43.8 mg g −1 for 8 and 17 nm CoCr 2 O 4 nanoparticles, respectively. • Our results demonstrates the dye removal efficiency of CoCr 2 O 4 nanoparticles could be enhanced by reduction of size or/and improved dispersibility. • With an ease of use CoCr 2 O 4 nanoparticles have the potential to be used as an organic dye removal adsorbent for wastewater treatment.