Effect of Optical Properties on Ag/MWCNTs Nanostructured Materials Prepared by Laser Physical Method for the Removal of Methylene Orange dye: Kinetic and Isotherm Studies

Ag NPs incorporated with MWCNTs were carried with different amounts based on the ablation time during the pulsed laser ablation method of Ag target immersed in functionalized MWCNTs for enhancing the deterioration of clean water from waste treatment of methylene orange dye (MO) associated with kinetic, isotherm and suitable mechanism. This decoration procedure improves deterioration based on their optical features, especially studied by the Tauc energy band gap and Urbach energy. These are the key roles and early signals of the degradation process. So, the transmission, absorption, absorption coefficient, skin depth factor, energy band gap with correct transition type parameter, Urbach energy, and disorder were investigated. It showed that the Tauc energy band gap and Urbach energy were 4.6:4.0 eV tunings from 0.89:1.29 eV, respectively, due to the excitation of an electron from the valence band to the conduction band and the surface plasmon resonance of silver nanoparticles. This property affects charge–transfer energy, an important photocatalytic activity marker. After that, the chemical-catalytic efficiency of the nanocomposites was evaluated using 2%, 5%, and 10% Ag NPs doping on the same amount of MWCNTs against MO in the presence of a reducing agent. The optimum parameters for making a high-impact degradation were produced by preparing Ag/MWCNTs nanocomposite with 40 min laser ablation to generate 26 µg incorporation of Ag NPs with MWCNTs. It required 40 min reaction times for degrading 79% of 5 mg/L MO dye at 40oC reaction temperatures. Then, Adsorption kinetics were carried out by the pseudo-first-order and pseudo-second-order models to analyse the actual adsorption data and elucidate the mechanism of MO adsorption on the nanocomposites, which the adsorption data fit the pseudo-first-order model better. After that, the adsorption thermodynamic parameters were investigated based on the activation energy (E_a), energy change (∆G°), entropy change (∆S°), and enthalpy change (∆H°), which show Ag/MWCNTs adhesion was most likely based on physisorption.