Silver, copper, and cobalt trimetallic nanoparticles; synthesis, characterization and its application as adsorbent for acid blue 7 dye

Abstract

Abstract The synergistic effects of metal complex nanoparticles in remediation of environment had opened a versatile field of research as providing differential attractive forces for a given pollutant on their surfaces. Herein, trimetallic nanoparticles of silver, copper and cobalt (Ag–Cu–Co TNPs) were prepared via chemical reduction method using sodium borohydride as reductant which were then characterized through SEM, EDX, XRD and FT-IR analytical techniques. As model dye, acid blue 7 was adsorbed on the surface of fabricated particles utilizing batch adsorption approach. The adsorption conditions like temperature, adsorbent dosage, pH, and contact time were optimized to get maximum adsorption of the selected dye which were; 333 K, 0.01 g, pH 6 and 30 min respectively. The adsorption data were analyzed using kinetic and isotherm models, with the linear pseudo 2nd order kinetics and Langmuir models being the most suitable. The maximum adsorption capacity at 333 K was found to be 74.07 mg/g. Thermodynamic variables such as entropy (ΔS°), enthalpy (ΔH°), and Gibbs free energy (ΔG°) changes were calculated to understand the adsorption feasibilities. Results indicated that the adsorption process was endothermic (ΔH° = 6.867 KJ mol−1) and spontaneous ΔG° (J mol−1) −219.2, −702.9 and −1086.6 at 293 K, 313 K and 333 K respectively. The entropy change (ΔS° = 24.185 J mol−1 K−1) suggested an increased disorder at the solid–solution interface during adsorption.