Removal of Reactive Orange 12 from aqueous solutions by adsorption on tin sulfide nanoparticle loaded on activated carbon

In the present study, tin sulfide nanoparticle loaded on activated carbon simply was synthesized and characterized using different techniques such as SEM, XRD and UV-analysis. Then, this new efficient adsorbent was used for Reactive Orange 12 (RO-12) adsorption. To improve the efficiency of adsorption effect of variables viz. pH, mass of SnS-NP-AC, initial dye concentration, contact time and temperature were examined and optimized. The adsorption mechanism and rate of processes was investigated by analyzing time dependency data to various conventional kinetic models such as pseudo-first-order and second order, Elovich and intra-particle diffusion models. Among them it was found that adsorption followed the pseudo-second-order kinetic model with good agreement between the equilibrium experimental and expected adsorption data. High fitting with the Langmuir models shows heterogeneous surface and mono-layer nature adsorption of Reactive Orange 12 on the SnS-NP-AC. Thermodynamic parameters such as enthalpy (ΔH), entropy (ΔS), activation energy (Ea), of sticking probability (S*) and Gibbʹs free energy changes (ΔG) were also calculated. It was seen that the proposed adsorbent has high tendency and adsorption capacity for RO-12 adsorption in a feasible, spontaneous and endothermic fashion.