Collaborative impact of Cu/TiO2 nano composites for elimination of cationic dye from aqueous solution: Kinetics and isothermal modeling

Abstract

Nano TiO2 is economic nano particles have many applications. This study focus on evaluation of Cu/TiO2 nano composites mechanically prepared for elimination of methylene blue dye (MB) in its aqueous solutions. Two molar ratios of TiO2 to Cu were used for the fabricated nano composites; (1:1)(TC1) and (2:1)(TC2). The fabricated doped particles were characterized by N2 adsorption–desorption isotherm, (FTIR) and (SEM/ EDAX) techniques. The results clarify that Cu atoms were randomly covered or precipitated on TiO2 nano particles resulting to increase in the porosity and surface roughness. The uptake study was conducted via batch mode under various processing parameters like pH, contact time, initial dye concentration and adsorbent mass. The results revealed that, maximum uptake 77–90 mg/g was achieved at solution pH = 5 for TiO2 and pH = 7 for doped TiO2 with an equilibrium time 6 h for studied samples. Removal % was in order TC1 > TC2 > T which correlated to the amount of deposited Cu in nano composites. Besides, the adsorption capacity increased by increasing the adsorbent mass and much reduced by boosting the dye concentration. This is explained due to the electrostatic interaction between benzene ring in MB and the electron cloud of Cu molecules. Pseudo 2nd order kinetic model was more appropriate to describe the adsorption of MB onto doped TiO2 nano particles and the experimental data were more fitting to Freundlich model suggesting a heterogeneous adsorption.

Keywords

• Cu/TiO2 nano composites
• Methylene blue
• Adsorption