Effective Catalytic Degradation of Organic Dyes by Nickel Supported on Hydroxyapatite-Encapsulated Cobalt Ferrite (Ni/HAP/CoFe2O4) Magnetic Novel Nanocomposite

Abstract

The present study reports the synthesis, characterisation and efficiency in the degradation of organic dye of nickel/hydroxyapatite/cobalt ferrite (Ni/HAP/CoFe2O4) novel nanocomposite. The composite was applied as both nanoadsorbent and heterogeneous catalyst for the degradation of organic dyes methylene blue and methyl orange. The composite was not very effective in the degradation of the dyes by adsorption method. However, in the presence of H2O2, significant catalytic degradation of both the dyes was observed. The catalyst showed a degradation of about 90% (methyl orange) and 99.1% (methylene blue) in 90 min in the presence of hydrogen peroxide. Reactive oxygen species (ROS), such as hydroxyl and perhydroxyl radicals (HO• and HOO•), were formed and Fenton and Fenton-like mechanisms were involved in the decolourisation process. Kinetic studies showed that the degradation process followed first-order. The nanocomposite Ni/HAP/CoFe2O4 showed high catalytic activity, stability and superparamagnetic property.