Co-Enzymes based nanoflowers incorporated-magnetic carbon nanotubes: A new generation nanocatalyst for superior removal of cationic and anionic dyes with great repeated use

Abstract

Synthetic dyes leading to substantial discharge in various industrial areas such as textile, plastics, food, and cosmetics, have growingly threatened all livings. Although enzymes have been used for dye degradation, weak stability against changes in reaction environment, lack of reusability and high cost have strictly limited their use. Herein, we have developed co-enzymes nanoflowers incorporated-magnetic carbon nanotube nanocomposite as a novel and efficient nanocatalyst for superior degradation of malachite green (MG) and acid orange 7 (AO7) as model cationic and anionic dyes with excellent cyclic use. The HRP-Lac NF@mCNT nanocomposite (NC) containing horseradish peroxidase–laccase nanoflower (HRP-Lac NF) and iron oxide nanoparticles (Fe 3 O 4 NPs) decorated magnetic carbon nanotube (mCNT) was systematically employed in dye degradation as functions of pH, reaction time, dye type and reusability. This HRP-Lac NF@mCNT nanocomposite acted as one malfunctional nanoplatform since both HRP and Lac enzymes were used for rapid and efficient dye removal, Fe 3 O 4 NPs provided cyclic use and omitting the centrifugation step, and CNT functioned as a unique platform for NFs and Fe 3 O 4 NPs deposition. We demonstrated that HRP-Lac NF@mCNT NC induced ∼ 90 % MG and ∼ 85% AO7 decolorization in 20 min at pH 7.4 while it almost completely decolorized MG and AO7 in 60 min. In addition, ∼ 95% MG and ∼ 85% AO7 decolorization were accomplished even after 16 cycling use of HRP-Lac NF@mCNT NC. We claim that HRP-Lac NF@mCNT NC induced dye decolorization with dual mechanisms, enzymatic degradation, and physical adsorption. • Preparation of horseradish peroxidase–laccase co-enzymes nanoflower incorporated-magnetic carbon nanotubes. • Rapid and efficient dye degradation against a cationic and an anionic dye. • Magnetic property for repeated use.