Novel N-doped CNTs stabilized Cu2O nanoparticles as adsorbent for enhancing removal of Malachite Green and tetrabromobisphenol A

Abstract

A newly designed N-doped CNTs stabilized Cu2O nanoparticles (PVP@CNTs-Cu2O) were fabricated and used to remove organic pollutants such as Malachite Green (MG) dye and tetrabromobisphenol A (TBBPA). The introduction of PVP here not only could stabilize Cu2O nanoparticles, but also act as active sites for adsorption of organic pollutants. The hybrid mesoporous adsorbent exhibited excellent adsorption performances for MG and TBBPA, which were mainly because of the synergistic effects of inorganic species and polymer. The maximum adsorption capacities of MG and TBBPA by PVP@CNTs-Cu2O were 1495.46 and 116.72mg/g, respectively, significantly higher than pristine CNTs (417.58 and 68.03mg/g, respectively). The adsorption of MG was independent of ionic strength. In contrast, the increase in ionic strength significantly inhibited the adsorption of TBBPA. Freundlich isotherm model fitted well with the experimental data of both MG and TBBPA adsorption, indicating the heterogeneous surface of PVP@CNTs-Cu2O. PVP@CNTs-Cu2O demonstrated rapid adsorption rates for both MG and TBBPA, and their adsorption kinetics were analyzed by the pseudo-first-order, pseudo-second-order and Elovich kinetic models. The possible mechanisms of MG and TBBPA adsorption was further explored by means of FTIR and XPS. High adsorption capacity, rapid kinetics, good reusability as well as simple preparation were important advantages for the practical application in MG and TBBPA removal by PVP@CNTs-Cu2O.